Data cartridge library

ABSTRACT

The present invention is directed to a data cartridge library that, in one embodiment, is comprised of: (a) a frame or cabinet that defines an interior space; (b) a multi-piece magazine that forms a portion of the frame; (c) a drive bay with a full-height drive space that is capable of accommodating a full-height drive and of being altered to accommodate two, half-height drives; (c) a picker that employs a crank that is capable of rotating 360 degrees and that carries a first cam driver that cooperates with a first cam follower to actuate a grasper that is capable of grasping and releasing a data cartridge, and a second cam driver that cooperates with a second cam follower to move the grasper towards and away from a location at which a data cartridge is located; (d) an elevator for moving the picker within a portion of the interior space and that is comprised of a first and second drive systems for respectively driving the first and second ends of an elevator carriage and a shaft for transferring power from the first drive system to the second drive system; (e) a robotics module that can be removed from the interior of the frame and is comprised of the picker and a substantial portion of the elevator; (f) an access port that allows a user to access the interior space and does not comprise a hinge; and (g) a universal bay that provides a space for accommodating electronic components that provide for enhanced operation and that can be divided into sub-spaces. Another embodiment of the invention is directed to a magazine that is used to move data cartridges into and out of the library via an entry/exit port. In one embodiment, the magazine comprises a box-structure that is capable of holding a plurality of data cartridges, a dust cover, and a coupling structure comprised of a member that extends away from the side wall of the box structure.

FIELD OF THE INVENTION

The present invention is directed to a data cartridge library that isuseful in storing data on a recording medium located in a cartridgeand/or retrieving data from a recording medium located in a cartridge.

BACKGROUND OF THE INVENTION

Presently, data cartridge libraries are primarily used to archive data,i.e., store data that is not immediately needed by a host computer, andprovide archived data to the host computer when the data is needed. Toelaborate, the typical data cartridge library receives data from a hostcomputer and causes the data to be stored or recorded on the recordingmedium located in one or more cartridges. When the host computerrequires some of the data that was previously stored in a datacartridge, a request for the data is sent from the host computer to thelibrary. In response, the library identifies the data cartridge(s) inwhich the desired data is located, retrieves the data from the recordingmedium with the cartridge(s), and transmits the retrieved data to thehost computer system.

Presently, most data cartridge libraries are comprised of: (a) aframe/chassis/cabinet that defines an interior space; (b) a magazinestructure that is located within the interior space and that provides aplurality of data cartridge storage spaces, which are each capable ofaccommodating at least one data cartridge; (c) one or more drives thatare each located within the interior space and capable of writing dataonto a recording medium located in a data cartridge and/or reading datafrom the recording medium located in a data cartridge; (d) a datacartridge transport device that is located within the interior space andcapable of moving an individual data cartridge between any one of theplurality of data cartridge storage spaces and any one of the driveswithin the library; and (e) an interface for receiving data from andtransmitting data to a host computer.

Typically, such a data cartridge library is capable of both storing dataprovided by a host computer and retrieving data previously stored in thelibrary for the host computer. The storage of data involves using thetransport device to move a data cartridge from one of the data cartridgestorage spaces to a drive, using the drive to write the data provided bythe host computer on the recording medium located within the cartridge,and after the data has been written on the recording medium, using thetransport device to move the data cartridge from the drive to a datacartridge storage space. The retrieval of data involves using thetransport device to move a data cartridge from one of the data cartridgestorage spaces to a drive, using the drive to read the data on therecording medium located within the cartridge and provide the read datato the host computer, and after the data has been read from therecording medium, using the transport device to move the data cartridgefrom the drive to a data cartridge storage space.

As previously noted, a data cartridge library is comprised of a datacartridge transport that is capable of being used to move a datacartridge between any one of the magazine data cartridge storagelocations and any one of the drives in the library. Typically, the datacartridge transport device is comprised of a picker and an elevator thatmoves the picker within the interior space. The picker is capable ofinserting/extracting a data cartridge into/from any one of the magazinestorage spaces and any one of the drives. Typically, the picker iscomprised of: (a) a grasping device that is used to engage a datacartridge and (b) a pusher plate that carries the grasping device andthat is capable of movement towards and away from a location that iscapable of accommodating a data cartridge. The elevator serves toposition the picker adjacent to a location that is capable ofaccommodating a data cartridge so that the picker can perform aninsertion or extraction operation.

In an extraction operation, the elevator is used to position the pickeradjacent to a space at which a data cartridge is located (typically,either a storage space associated with the magazine or a drive). Afterthe picker has been positioned, the pusher plate is used to move thegrasping device towards the data cartridge. After the grasping devicehas been positioned, the grasping device is then actuated to grasp thecartridge. At this point, the pusher plate is then moved away from thelocation at which the data cartridge was located to extract the datacartridge from the space.

In an insertion operation, the elevator is used to position the picker(which is assumed to be grasping a data cartridge) adjacent to the spaceat which a data cartridge is to be located. After the picker has beenpositioned, the pusher plate is then used to move the grasping deviceand the grasped data cartridge towards the space in which the datacartridge is to be located. After the pusher plate and grasping devicehave positioned the data cartridge in the space, the grasping devicereleases the data cartridge, and the pusher plate is moved away from thespace to retract the grasping device.

Many data cartridge libraries are also comprised of an entry/exit portthat allows a user to insert and/or extract a data cartridge from thelibrary without powering down the transport device. To elaborate, absentan entry/exit port, if a user wants to insert/extract a data cartridgeinto/from a library, the user typically powers down the transport deviceto avoid being injured by the transport device during the insertion orextraction of the data cartridge. The entry/exit port allows a user toinsert/extract a data cartridge into/from the library without beingexposed to the transport device. As a consequence, the entry/exit portallows a data cartridge to be inserted/extracted into/from the librarywithout having to power down the transport device. Typically, an entryexit port is comprised of a slot structure that defines at least oneslot that is capable of accommodating at least one data cartridge and adevice that places the structure in one of two states. In the firststate, the device positions the slot structure such that a slot isexposed to the exterior environment. When the structure is in thisstate, a user can either insert a data cartridge into the slot or removea data cartridge from the slot, without being exposed to the transportdevice in either case. In the second state, the device positions theslot structure such that a slot is exposed to the interior of thelibrary and accessible by the transport device, which can either inserta cartridge into the slot or remove a cartridge from the slot. When thestructure is in the second state, the user is not exposed to thetransport device.

One type of entry/exit port that has evolved is comprised of: (a) aframe or support to/from which a magazine that can accommodate multipledata cartridges can be attached/detached; and (b) a device for placingthe frame in one of the states. In the first state, the device positionsthe frame such that the frame is exposed to the exterior environment.When the structure is in this state, a user can either attach a magazineto the frame or detach a magazine from the frame. Further, the user caneither insert/remove one or more data cartridges into/from the magazine.In the second state, the device positions the frame such that anymagazine that is attached to the frame is exposed to the transportdevice. In this state, the transport device can load data cartridgesinto the magazine or remove data cartridges from the magazine, asneeded. When the frame is in either state, a user is substantiallyshielded from the transport device.

Many data cartridge libraries also have a hinged door that allows a useraccess to the interior of the library. Typically, such a door isprovided so that the transport device can be accessed for maintenanceand repair.

SUMMARY OF THE INVENTION

The present invention is directed to a data cartridge library that iscomprised of: (a) a frame/chassis/cabinet; (b) a data cartridge magazinethat provides a plurality of data cartridge storage spaces that are eachcapable of accommodating at least one data cartridge; (c) a drive thatis capable of writing data onto a recording medium located within acartridge and/or reading data from a recording medium located in acartridge; (d) a picker that is capable of being used to insert andextract a data cartridge from a space that is capable of accommodating adata cartridge; and (e) an elevator for moving the picker within thelibrary so that a data cartridge can be transported between any one ofthe plurality of magazine data cartridge storage spaces and any one ofthe drives within the library.

In one embodiment, the data cartridge library comprises a picker that iscomprised of: (a) a base plate that is operatively connected to anelevator; (b) a grasper that is operatively connected to the base plateand comprised of a pair of members that are capable of being placed in aclosed position that is suitable for grasping a data cartridge and anopen position that is suitable for releasing a grasped data cartridge;and (c) a crank that is operatively connected to the base plate andcapable of rotating about an axis. The picker further comprises agrasper cam structure comprised of a cam driver that is associated withthe crank and a cam follower that is associated with the grasper. Thecam driver and the cam follower are situated such that rotation of thecrank brings the cam driver into contact with the cam follower and, inso doing, places the grasper in one of the closed position and the openposition. Unlike known pickers that employ a crank and a cam structureto actuate a grasper, the grasper is placed in a closed position over afirst range of rotation of the crank and an open position over a secondrange of rotation of the crank that substantially does not overlap withthe first range of rotation. In one embodiment, the first and secondranges are each about 180 degrees.

In one embodiment, the data cartridge library comprises a picker that iscomprised of: (a) a base plate that is operatively connected to anelevator; (b) a grasper that is operatively connected to the base plateand comprised of a pair of members that are capable of being placed in aclosed position that is suitable for grasping a data cartridge and anopen position that is suitable for releasing a grasped data cartridge;and (c) a crank that is operatively connected to the base plate andcapable of rotating about an axis. The picker further comprises agrasper cam structure comprised of a cam driver that is associated withthe crank and a cam follower that is associated with the grasper. Thecam driver and the cam follower are situated such that rotation of thecrank brings the cam driver into contact with the cam follower and, inso doing, places the grasper in one of the closed position and the openposition. Unlike known pickers that employ a crank and a cam structureto actuate a grasper, the crank is capable of rotating through more than180 degrees.

In one embodiment, the crank is capable of rotating through 360 degrees.In a particular embodiment in which the crank is capable of such arotation, the picker is further comprised of a pusher plate thatsupports the grasper and a pusher plate cam structure that is used tomove the pusher plate towards and away from a space that is capable ofaccommodating a data cartridge. The pusher plate cam structure iscomprised of a pusher plate cam driver that is associated with the crankand a pusher plate cam follower that is associated with the pusherplate. The grasper cam structure and pusher cam structure are situatedsuch that: (a) for 180 degrees of a 360 degree rotation of the crank,the grasper is placed in a closed position and the pusher plate can bemoved between a fully retracted and a fully extended position; and (b)for the other 180 degrees of a 360 degree rotation of the crank, thegrasper is placed in an open position and the pusher plate can be movedbetween a fully retracted position and a fully extended position.

In another embodiment, the data cartridge library is comprised of apicker that is, in turn, comprised of a base plate, grasper, crank thatis capable of rotation about an axis, and a grasper cam structure. Thegrasper cam structure is comprised of a cam driver that is associatedwith the crank and a cam follower that is associated with the grasper.The grasper cam driver has a surface vector that is not substantiallyperpendicular to the axis or rotation of the crank. In one embodiment,the grasper cam driver comprises a bubble-like or spherical section thathas such a surface vector. In a further embodiment, the picker iscomprised of a pusher plate and a pusher plate cam structure with apusher plate cam driver that is associated with the crank. The pusherplate cam driver has a surface vector, in contrast to the grasper camdriver, that is substantially perpendicular to the axis of rotation ofthe crank. In one particular embodiment, the pusher plate cam structureoperates to move the pusher plate in a direction that is substantiallyperpendicular to the axis of rotation of the crank and the grasper camstructure operates such that the grasper cam follower is displaced in adirection that at least has a component vector that is parallel to theaxis of rotation of the crank.

In another embodiment, a data cartridge library is provided that allowsa user to readily remove/insert a transport module from/into thelibrary, where the transport module is comprised of a picker and asubstantial portion of an elevator. In one embodiment, the library iscomprised of: (a) a frame/chassis/cabinet; (b) a data cartridgemagazine; (c) a drive; (d) a picker that is capable of being used toinsert and extract a data cartridge from a space that is capable ofaccommodating a data cartridge; and (e) an elevator for moving thepicker within the library so that a data cartridge can be transportedbetween any one of the plurality of magazine data cartridge storagespaces and any one of the drives within the library. The library isfurther comprised of a transport module that is comprised of a supportstructure, a portion of the elevator that is connected to the supportstructure, and the picker. A user-actuatable connector is also providedthat allows a user to attach the transport module to the frame of thelibrary and to detach the transport module from the frame so that themodule can be removed from the library.

In one embodiment of a data cartridge library with aremovable/insertable transport module, the elevator is comprised of anelevator carriage that supports the picker, a first drive system fordriving one end of the carriage, a second drive system for driving theother end of the carriage, an electric motor that is operativelyconnected to the first drive system and provides the first drive systemwith energy for moving the first end of the carriage. The elevator isfurther comprised of a shaft that connects the first drive system to thesecond drive system, thereby allowing energy from the motor to betransferred through the first drive system to the second drive system.So that the transport module can be removed from the library, the shaftis capable of be separated into two pieces by actuation of auser-actuatable connector. In one embodiment, the connector is comprisedof a spline associated with a free end of one piece of the shaft and aspline collar that is associated with the free end of the other piece ofthe shaft. By sliding the spline collar away from the spline, the twopieces of the shaft are disconnected to facilitate removal of thetransport module from the library. To connect the two pieces of theshaft, the free ends of the shaft are aligned and the spline collar isslide over the spline.

In yet another embodiment, a data cartridge library is provided in whicha shaft, rather than a pulley system, is used to connect two drivestructures that are used to drive the ends of an elevator carriage thatsupports a picker. In one embodiment, the library is comprised of: (a) aframe/chassis/cabinet; (b) a data cartridge magazine; (c) a drive; (d) apicker that is capable of being used to insert and extract a datacartridge from a space that is capable of accommodating a datacartridge; and (e) an elevator for moving the picker within the libraryso that a data cartridge can be transported between any one of theplurality of magazine data cartridge storage spaces and any one of thedrives within the library. The elevator is comprised of an elevatorcarriage that supports the picker, a first drive system for driving oneend of the carriage, a second drive system for driving the other end ofthe carriage, an electric motor that is operatively connected to thefirst drive system and provides the first drive system with energy formoving the first end of the carriage. The elevator is further comprisedof a shaft that connects the first drive system to the second drivesystem, thereby allowing energy from the motor to be transferred throughthe first drive system to the second drive system.

In yet another embodiment, a data cartridge library is provided with adoor that allows a user access to the interior of the library and thatis not constrained to rotate about an axis when moving between open andclosed positions. In one embodiment, the library is comprised of: (a) aframe/chassis/cabinet with a top surface, bottom surface, and sidesurface extending between the top and bottom surfaces; (b) a datacartridge magazine; (c) a drive; (d) a picker that is capable of beingused to insert and extract a data cartridge from a space that is capableof accommodating a data cartridge; and (e) an elevator for moving thepicker within the library so that a data cartridge can be transportedbetween any one of the plurality of magazine data cartridge storagespaces and any one of the drives within the library. The library isfurther comprised of a user interface that is associated with the sidesurface of the frame and is exposed to the exterior environment. Invarious embodiments, the user-interface comprises an output terminal forproviding a user with information relating to the library, an inputterminal for allowing a user to interact with the library, an entry/exitport, and combinations of the these elements. The side surface iscomprised of a displaceable portion that accommodates the userinterface. The displaceable portion is capable of being placed in an“open” condition that allows a user access to the magazine, drive(s),picker and elevator and a “closed” condition that prevents user accessto the noted elements. The library further comprises a user-actuatableconnector that permits a user to place the displaceable portion ineither the open or closed conditions. However, unlike hinged doors, thedisplaceable portion and the user-actuatable connector do not constrainthe displaceable portion to rotate about an axis in moving between openand closed positions. In one embodiment, the user-actuatable connectorcomprises one or more captured screws that allow the displaceableportion to be detached from the frame to expose the interior of thelibrary or attached to the frame to cover the interior of the library.

In another embodiment, a data cartridge library is provided that has amulti-piece magazine. In one embodiment, the library is comprised of:(a) a frame/chassis/cabinet; (b) a data cartridge magazine; (c) a drive;(d) a picker that is capable of being used to insert and extract a datacartridge from a space that is capable of accommodating a datacartridge; and (e) an elevator for moving the picker within the libraryso that a data cartridge can be transported between any one of theplurality of magazine data cartridge storage spaces and any one of thedrives within the library. In one embodiment, the magazine is amulti-piece structure that forms a channel with a first side, a secondside, and a back side that extends between the first and second sides.The first, second and back sides cooperatively define an interior spacethat is capable of accommodating a plurality of data cartridges. Themulti-piece magazine structure is comprised of: (a) a first structurethat is in the form of a U-shaped channel that forms portions of thefirst and second sides of the magazine and the back side of themagazine; (b) a second structure that forms portions of the first andsecond sides; and (c) a coupler for connecting the first and structuresto one another. The first structure also serves as a portion of theframe of the library and, in one embodiment, is made of metal. Thesecond structure is made of the same type of material as the cartridges(typically, plastic) in one embodiment.

The present invention further provides a multi-piece magazine that issuitable for use in a data cartridge library. In one embodiment, themagazine resulting for the joining together of the various pieces formsa channel with a first side, a second side, and a back side that extendsbetween the first and second sides. The first side, second side and backside cooperatively define an interior space that is capable ofaccommodating a plurality of data cartridges. The multi-piece magazinestructure is comprised of: (a) a first structure that forms at least aportion of the back side of the magazine; (b) a second that structurethat forms at least portions of the first and second sides; and (c) acoupler for connecting the first and second structures to one another.In one embodiment, the first structure is in the form of a U-shapedchannel that forms portions of the first and second sides of themagazine and a substantial portion of the back side of the magazine. Thesecond structure, in addition to providing at least portions of thefirst and second sides of the magazine, further comprises a pair of endsides that are separated from each other and that each connect theportions of the first and second sides provided by the second structureto one another, thereby forming a closed-loop structure. The couplerconnects the first and second structures to one another so as to form abox-like, magazine structure with an open side through which cartridgescan be inserted/removed into/from the magazine structure.

The present invention also provides a magazine that is capable of beingattached/detached to/from an entry/exit port structure. The magazine iscomprised of: (a) a box structure with a bottom wall and a side wallthat extends from the bottom wall to a terminal edge that defines anopening for the insertion/extraction of data cartridges into/from themagazine; (b) a plurality of partitioning structures that partition theinterior space of the magazine into a plurality of slots that are eachcapable of accommodating at least one data cartridge; and (c) a couplingstructure that allows the box structure to be attached/detached to/froman entry/exit port structure. In one embodiment, the coupling structureis comprised of a first substantially rigid flange that extends awayfrom a first side wall portion and a second substantially rigid flangethat extends away from a second side wall portion that is separated fromand substantially parallel to the first side wall portion. In oneembodiment, the first and second flanges are located in an asymmetricmanner so that the box structure can only be mounted to the entry/exitport structure in a particular orientation.

The present invention further provides a data cartridge library with anentry/exit port that has a frame that can be readily attached anddetached to facilitate maintenance of the entry/exit port. In oneembodiment, the library is comprised of: (a) a frame/chassis/cabinet;(b) a data cartridge magazine; (c) a drive; and (d) a transport assemblythat is capable of moving a data cartridge between any one of theplurality of magazine data cartridge storage spaces and the drive. Thelibrary is further comprised of an entry/exit port for moving entry/exitport magazines between an exterior environment and an interiorenvironment of the library where the magazine is accessible to thetransport device. In one embodiment, the entry/exit port comprises amount to which a magazine can be attached and from which a magazine canbe detached, a guide structure for constraining the movement of themount between a first position at which a user can attach/detach amagazine to/from the mount and a second position at which the transportassembly is capable of inserting/removing a data cartridge into/from amagazine attached to the mount, and a motive device for providing themotive force for moving the mount between the first and secondpositions. The entry/exit port further comprises a “stop” structure thatis attached to the mount and operates to prevent the mount from beingmoved beyond the first position. A quick release structure allows thestop structure to be quickly detached from the mount so that the mountcan be readily removed from the library.

The present invention also provides a data cartridge library with adrive bay that is capable of accommodating a full-height drive and beingaltered to accommodate two, half-height drives. In one embodiment, thelibrary is comprised of: (a) a frame/chassis/cabinet; (b) a datacartridge magazine; and (c) a transport assembly that is capable ofmoving a data cartridge between any one of the plurality of magazinedata cartridge storage spaces and any one of the drives within thelibrary. The library is further comprised of a drive bay that provides afull-height drive space that is capable of accommodating a full-heightdrive and a partition mount for supporting a partition that allows thefull-height drive space to be divided into two, half-height drive spacesthat are each capable of accommodating a half-height drive. In oneembodiment, the full-height drive space is capable of: (a) accommodatinga full-height drive that is located within a full-height drive sled; or(b) when a partition engages the partition mount, accommodating two,half-height drives that are each located within a half-height drivesled. In other embodiments, the library is further comprised ofcombinations of full-height and half-height drives located in the drivebay.

The present invention also provides a data cartridge library with auniversal bay that is capable of accommodating one of more electronicdevices that are not necessary to the operation of the library but canbe used to enhance or supplement the operation of the library. In oneembodiment, the library is comprised of a frame/chassis/cabinet thatdefines an interior space. The interior space is partitioned into: (a) adata cartridge space that provides storage locations for all of thecartridges that the library is capable of storing; (b) a drive spacethat provides locations for all of the drives that the library iscapable of supporting; (c) a transport assembly space for accommodatingthe movement of a picker and elevator in moving a data cartridge betweenany one of the data cartridge storage locations and any one of thedrives within the library; (d) a power supply space for housing all ofthe power supplies that the library is capable of supporting; and (e)circuitry space for housing circuitry that is used to distribute powerwithin the library and control the operation of the transport assembly.The library is further comprised of a universal bay that defines auniversal space which can be used to house circuitry other than thecircuitry located in the circuitry space and does not comprise any ofthe other noted spaces. In one embodiment, the universal bay comprises apartition mount that is capable of supporting a partition that is usedto divide the universal space into subsidiary spaces, each capable ofaccommodating circuitry that enhances or supplements the operation ofthe library.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B illustrate the exterior of an embodiment of a data cartridgelibrary that is capable of processing LTO tape cartridges;

FIG. 2 is an exploded view of the embodiment of the data cartridgelibrary illustrated in FIGS. 1A-1B;

FIGS. 3A-3B illustrates an LTO tape data cartridge;

FIGS. 4A-4B illustrate a DLT tape data cartridge;

FIGS. 5A-5B illustrate a displaceable portion of the side of the housingof library shown in FIGS. 1A-1B that allows a user to access theinterior of the library;

FIGS. 6A-6C illustrate an entry/exit port associated with the datacartridge library illustrated in FIGS. 1A-1B;

FIGS. 7A-7F illustrate a cartridge magazine that can beattached/detached to/from the entry/exit port illustrated in FIGS. 6A-6Cand portions of the magazine;

FIGS. 8A-8E illustrate a multi-piece magazine for storing a plurality ofLTO tape cartridges and that is associated with the library shown inFIGS. 1A-1B;

FIGS. 9A-9F illustrate a drive bay that is associated with the libraryshown in FIGS. 1A-1B and capable of accommodating multiple full-heightdrives and be adapted to accommodate half-height drives within a spacethat is capable of accommodating one of the full-height drives;

FIGS. 10A-10B illustrate the space within the library shown in FIGS.1A-1B that is used to house power supplies and circuitry fordistributing electrical power to various power consuming componentswithin the library;

FIGS. 11A-11C a universal bay that is associated with the library shownin FIGS. 1A-1B and capable of accommodating circuitry that enhances ofsupplements the operation of the library but is not necessary to theoperation of the library;

FIGS. 12A-12F illustrate the transport system that is associated withthe library shown in FIGS. 1A-1B;

FIG. 13A-13B illustrates aspects of the robotics module that can bereadily inserted into and removed from the library illustrated in FIGS.1A-1B;

FIGS. 14A-14F illustrate the picker that is associated with the libraryshown in FIGS. 1A-1B;

FIGS. 15A1-15D2 illustrate the operation of the picker in grasping anLTO tape cartridge; and

FIGS. 16A-16D illustrate the ranges of rotation of the crank duringwhich the grasper assembly is in the open position and in the closedposition.

DETAILED DESCRIPTION

With reference to FIGS. 1A, 1B and 2, an embodiment of a data cartridgelibrary 100 (hereinafter referred to as “library 100”) is described.Generally, the library is comprised of: (a) a frame/chassis/cabinet 102that defines an interior space for containing the other components ofthe library; (b) entry/exit port 104 for moving data cartridges into andout of the library; (c) a magazine structure 106 for providing aplurality of data cartridge storage spaces that are each capable ofaccommodating at least one data cartridge; (d) a drive bay 108 forhousing a plurality of drives; (e) a plurality of drives 110 located ina drive bay 108, with each drive capable of writing/reading dataonto/from a recording medium located in a cartridge; (f) a transportsystem 112 for moving a data cartridge between any one of the datacartridge storage spaces provided by the magazine structure 106 and anyone of the drives 108; (g) a power supply/control module bay 114 forhousing at least one power supply and control circuitry that is deemednecessary to the operation of the library; (h) a pair of power supplies116A, 116B that are each located in the power supply/control module bay114; (g) a library control module 118 located in the powersupply/control module bay 114; and (h) a universal bay 120 for housingelectronic circuitry that enhances or supplements the operation of thelibrary but is not deemed necessary to the operation of the library.

Before describing the library 100 in greater detail, the data cartridgesthat the library 100 is adapted to manipulate are described. The library100 is adapted for operating on magnetic tape cartridges. Specifically,the library 100 is adapted for operating on cartridges that conform tothe following cartridge formats: (a) LTO (linear tape open) and (b) DLT(digital linear tape). It should, however, be appreciated that thelibrary 100 can be adapted to operate on magnetic tape cartridge thatconform to other cartridge formats, such as AIT (advanced intelligenttape), SAIT (super advanced intelligent tape), Travan, and the like.Further, it should be appreciated that the library can be adapted tooperate on cartridges that contain other types of recording mediums,such as magnetic disk, optical disk and optical tape mediums.

With reference to FIGS. 3A-3B, an LTO tape cartridge 130 comprises afirst cartridge face 132A, a second cartridge face 132B, a firstcartridge side 134A, a second cartridge side 134B, a first cartridge end136A, and a second cartridge end 136B. The distance between the firstand second cartridge faces 132A, 132B defines the height of thecartridge, which is 0.85 in. The distance between the first and secondside surfaces 134A, 134B defines the width of the cartridge, which is4.15 in. The distance between the first and second ends 136A, 136Bdefines the depth of the cartridge, which is 4.02 in. The cartridgefurther comprises an orientation feature 138 that provides a basis forproperly orientating the cartridge for insertion in to an LTO tape driveso that data can be read from and/or written to the recording mediumwithin the cartridge. The orientation feature 138 also provides a basisfor orienting all of the LTO tape cartridges stored within the library100 in the same manner. The cartridge also comprises a first pair ofgripper notches 140A, 140B and a second pair of gripper notches 142A,142B, with one or both pair of notches typically used by a device thatgrips the cartridge during transport between a magazine and a drive.

With reference to FIGS. 4A-4B, a DLT tape cartridge 150 comprises afirst cartridge face 152A, a second cartridge face 152B, a firstcartridge side 154A, a second cartridge side 154B, a first cartridge end156A, and a second cartridge end 156B. The distance between the firstand second cartridge faces 152A, 152B defines the height of thecartridge, which is 1.00 in. The distance between the first and secondside surfaces 154A, 154B defines the width of the cartridge, which is4.15 in. The distance between the first and second ends 156A, 156Bdefines the depth of the cartridge, which is 4.16 in. The cartridgefurther comprises an orientation feature 158 that provides a basis forproperly orientating the cartridge for insertion into a DLT tape driveso that data can be read from and/or written to the recording mediumwithin the cartridge. The orientation feature in an actual DLT issomewhat more complex than the feature shown in FIG. 4A. The orientationfeature 158 also provides a basis for orienting all of the DLT tapecartridges stored in the library 100 in the same manner. The cartridgealso comprises a single gripper notch 160, which is typically used by adevice that grips the cartridge during transport between a magazine anda drive. The DLT tape cartridge 150 further comprises a recess 162 inthe first end 156A that is typically used for to hold a label, such as abar-code label, that is used to identify the cartridge.

Having described the tape data cartridges on which the library 100operates, the library 100 is now described in greater detail. Withreference to FIGS. 1A-1B, the library 100 comprises a front side 170A, arear side 170B, a first lateral side 170C, a second lateral side 170D, atop side 170E, and a bottom side 170F.

Associated with the front side 170A of the library 100 is the entry/exitport 104 and a power button 172 that allows a user to control theapplication of electrical power from the power supplies 116A, 116B tocomponents of the library. Also associated with the front side 170A is atouch screen 172 that is used to output information relating to thelibrary 100 to a user and to allow a user to input information (e.g.,commands) to the library 100. Other types of input and outputperipherals can be used in place of the touch screen 106. For instance,a screen can be provided to output information to a user and a keyboardcan be provided to allow a user to input information. A front panel 176that provides ports for accommodating the entry/exit port 104, the powerbutton 172 and the touch screen 172 is also associated with the frontside 170A. The front panel 176 is also capable of being removed by auser to allow the user to access the interior of the library 100.

Associated with the rear side 170B of the library 100 is access to thespace within the drive bay 108, which allows a user to insert/remove adrive into/from the drive bay 108. User access to the powersupply/control module bay 114 is also associated with the rear side170B. Specifically, a user can insert/remove a power supply and/orinsert/remove a library control module via the access provided to thepower supply/control module bay 114 at the rear side 170B. Alsoassociated with the rear side 170B is access to the space within theuniversal bay 120. In the embodiment of the library illustrated in FIG.1B, a pair of quad-interface processors are resident in the spacedefined by the universal bay 170B.

The first lateral side 170C comprises a cosmetic exterior skin 178A.Underlying the skin 178A is: (a) a side portion 180A of a top tray 182,(b) a side portion 184A of a bottom tray 186, and (c) portions of themagazine structure 106 that connect the side portion 180A and the sideportion 184A. The side portion 184A also accommodates a rail thatfacilitates rack mounting of the library 100. Similarly, the secondlateral side 170D comprises a cosmetic exterior skin 178B. Underlyingthe skin 178B is: (a) a side portion 180B of a top tray 182, (b) a sideportion 184B of a bottom tray 186, and (c) portions of the magazinestructure 106 that connect the side portion 180B and the side portion184B. The side portion 184B also accommodates a rail that facilitatesrack mounting of the library 100.

The top side 170E comprises a mid-portion 188 of the top tray 182 thatextends between the side portions 180A, 180B. Similarly, the bottom side170F comprises a mid-portion 190 of the bottom tray 186.

The top tray 182, bottom tray 186, and the portions of the magazinestructure 106 that connect the top tray 182 and the bottom tray 186 formthe frame 102, i.e., the structure that supports the other elements ofthe library and defines an interior space in which the other elements ofthe library reside. It should be appreciated that other frame structuresare also feasible.

With reference to FIGS. 5A-5B, the removable front panel 176 isdescribed in greater detail. Generally, the removable front panel 176comprises a panel structure 200 and a plurality of captured screws 202,i.e. screws that can be actuated to attach/detach the front panel 176from the remainder of the library 100 but that remain attached to thepanel structure 200 to prevent loss. A plurality of threaded holes 204,each for engaging one of the captured screws 202, are associated withportions of the library other than the front panel 176. When the frontpanel 176 is in place, as shown in FIG. 1A, each of the captured screws202 is accessible to a user and engages one of the threaded holes 204,thereby placing the front panel 176 in a “closed” state that prevents auser from accessing the interior of the library 100 via the openingcovered by the front panel 176. If a user wants to access the interiorof the library 100, the captured screws 202 are actuated to disengagethe screws from the threaded holes. After all of the captured screws 202have been disengaged from the threaded holes 204, the front panel 176can be removed to expose the interior of the library. The openingprovided by removal of the front panel 176 is sufficient to allow atransport module comprised of a picker and a substantial portion of anelevator and an associated tray to be inserted/removed into/from theinterior of the library 100. The front panel 176 also defines openings206A-206C that respectively accommodate the exit/entry port 104, thepower button 172, and the touch screen 174.

With reference to FIG. 5B, the front panel 176 is comprised of a sheetmetal portion 208 and a plastic portion 210 that is readilyattached/detached to/from the sheet metal portion 208 to expose at leastsome of the captured screws 202. The sheet metal portion 208 supportsall of the captured screws 202. Additionally, the sheet metal portion208 is comprised of: (a) a first screen portion 212 that allows air toflow from the exterior environment into the interior of the library tocool components located therein but prevents electro-magnetic radiationfrom escaping from the interior of the library; (b) a second screenportion 214 that permits a user to view the interior of the library whenthe front panel is in the closed state but prevents electro-magneticradiation from escaping from the interior of the library; (c) openings216A-216C that respectively form portions of the openings 206A-206C; (d)locator pin holes 218A-218C that cooperate with locator pins that areassociated with the plastic portion 210 to facilitate the mating of theplastic portion 210 to the sheet metal portion 208; and (e) socketportions 220A-220D of ball-and-socket clips (aka Tinneman clips) thatare used to attach/detach the plastic portion 210 to the sheet metalportion 208.

The plastic portion 210 comprises: (a) a window 222 that, when theplastic portion 210 is properly mated with the sheet metal portion 208,is located adjacent to the second screen portion 214 of the sheet metalportion 208; (b) openings 224A-224C that cooperate with the openings216A-216C to form the openings 206A-206C when the plastic portion 210 isproperly mated with the sheet metal portion 208; (c) locator pins226A-226C that cooperate with the locator pin holes 218A-218C tofacilitate alignment of the plastic portion 210 with the sheet metalportion 208 when mating the plastic portion 210 to the sheet metalportion; (d) balls 228A-228D for engaging the sockets 220A-220Dassociated with the sheet metal portion 208 to facilitateattachment/detachment of the plastic portion 210 to/from the sheet metalportion 208.

With reference to FIGS. 6A-6C, the entry/exit port 104 is of a type thatmoves a magazine frame or mount between an “open” position, as shown inFIG. 6A, and a “closed” position as shown in FIG. 1A. When the magazineframe is in the “open” position, a user can attach a magazine to themagazine frame. Further, if a magazine is attached to the magazine frameand the magazine frame is in the open position, a user can insert a datacartridge into the library by placing a data cartridge in one of theslots of the magazine (either before or after the magazine is attachedto the magazine frame) and then causing the magazine frame to move tothe “closed” position. After the magazine frame is in the “closed”position, the data cartridge is accessible to the transport assembly.Consequently, if desired, the transport assembly can be used to move thedata cartridge to any space within the library that is accessible to thetransport assembly and capable of storing the data cartridge. Oneadvantage of employing a magazine is that the magazine can be populatedwith multiple data cartridges, thereby allowing multiple data cartridgesto be loaded into the library at one time.

If, on the other hand, a magazine is attached to the magazine frame anda user wants to remove a data cartridge from the library, the magazineframe is placed in the “closed” position. If the desired data cartridgeis not already in the magazine, the transport assembly is used to movethe desired data cartridge to the magazine. After the desired datacartridge is loaded into the magazine, the magazine frame is caused tomove from the “closed” position to the “open” position so that the usercan remove the desired data cartridge from the magazine. One advantageof employing a magazine is that multiple data cartridges can be removedfrom library at one time, either by removing the cartridges from themagazine or disengaging the magazine from the frame.

With reference to FIGS. 6A-6C, the entry/exit port 104 is comprised of:(a) a magazine frame 240; (b) a guide structure 242 for supporting themagazine frame 240 and guiding the magazine frame between “open” and“closed” positions; (c) a drive mechanism 244 for applying a motiveforce to the magazine frame 240 to drive the magazine frame between the“open” and “closed” positions; and (d) a sensor system 246 for use indetermining when the magazine frame 240 is in the “open” position andwhen the magazine frame is in the “closed” position.

With continuing reference to FIGS. 6B-6C, the magazine frame 240 iscomprised of: (a) a top guide channel 248; (b) a bottom bracket 250; (c)a front side bracket 252 that is attached to the top guide channel 248and the bottom bracket 250; (d) a back side bracket 254 that is attachedto the top guide channel 248 and the bottom bracket 250; (e) a bottomrail 256 that is operatively attached to the bottom bracket 250; (f) arack 258 that is operatively attached to the bottom bracket 250; and (g)a stop 262, operatively attached to the bottom bracket 250, forpreventing the drive mechanism 244 from driving the magazine frame 240beyond the “open” and “closed” positions.

The front side bracket 252, back side bracket 254, a portion of the topguide channel 248 and a portion of the bottom bracket 250 form amagazine receptacle 264 for receiving a magazine.

Further, the front side bracket 252 and back side bracket 254 eachrespectively comprise a first flange engagement structure 268A andsecond flange engagement structure 268B that are each capable ofreceiving and engaging one of a pair of flanges associated with amagazine to secure the magazine within the receptacle 264. The first andsecond flange engagement structures 268A, 268B, if engaging the pair offlanges associated with a magazine, can also be disengaged from theflanges so that the magazine can be removed from the receptacle 264. Thefirst and second flange engagement structures 268A, 268B are locatedsuch that the magazine can only be received in the magazine receptacle264 when the magazine is in a particular orientation.

Also associated with the front side bracket 252 is a cover mountingbracket 270 that support a entry/exit port cover 272.

With continuing reference to FIGS. 6A-6C, the guide structure 242 iscomprised of a top guide structure 274 that engages the top guidechannel 248. The top guide structure 274 is comprised of a bracket 276that is attached to the exterior skin 178B and two pairs of rollers278A, 278B that each engage a flange of the top guide channel 248 toguide the magazine frame 240.

The guide structure 242 is further comprised of a bottom guide structure280 that engages the bottom rail 256. The bottom guide structure 280 iscomprised of a bracket 282 that supports rail brackets 284A, 284B. Therail brackets 284A, 284B capture the rail 256 and allow the rail 256 tobe linearly displaced so that the frame can be moved between the “open”and “closed” positions.

The drive mechanism 244 is comprised of the rack 258, a stepper motor288 that is attached to the mounting bracket 282, a pinion 290 that isattached to the spindle of the motor 286, and a cluster gear 292 thatconnects the rack 258 and the pinion 290. In operation, the steppermotor 288 produces a motive force that is used to translate the magazineframe 240 between the “closed” and “open” positions. More specifically,the stepper motor 288 produces a rotational motive force that istransferred to the rack 258 via the pinion 290 and the cluster gear 292.The interaction of the cluster gear 292 and the rack 258 translates therotation motive force into a translational motive force that is used tomove the magazine frame 240 between the “closed” and “open” positions.The stepper motor 288 is capable of being controlled so as to rotate thespindle in either a clockwise direction or a counter-clockwisedirection. Rotation of the motor spindle in the clockwise directioncauses the magazine frame 240 to move towards the “open” position.Conversely, rotation of the motor spindle in the counter-clockwisedirection causes the frame to move towards the “closed” position.

The sensor system 246 is comprised of a flag 294 that is attached to thebottom bracket 250 of the magazine frame 240, a first detector 296 fordetecting when the magazine frame 240 is in the “open” position and thatis attached to the mounting bracket 284B, a second detector 298 fordetecting when the magazine frame 240 is in the “closed” position. Thesecond detector 298 is supported by a bracket 300 that is attached tothe side portion 184B of the bottom tray 186. In operation, the sensorsystem 246 detects that the magazine frame 240 is in the “open” positionwhen the first detector 296 detects the flag 294. Similarly, the sensorsystem 246 detects that the magazine frame 240 is in the “closed”position when the second detector 298 detects the flag 294.

The sensor system 246 is further comprised of a comb flag 302 and athird sensor 304 that are used to determine the position of the frame240 when the frame 240 is located between the “open” and “closed”positions.

With continuing reference to FIGS. 6A-6C, the stop 262 engages a portionof the bracket 300 to prevent the drive mechanism 244 from driving themagazine frame 240 beyond the “closed” position. The stop 262 engagesthe bracket 282 to prevent the drive mechanism 244 from driving themagazine frame 240 beyond the “open” position. The stop 262 is attachedto the bottom bracket 250 by four screws 306. Notably, the magazineframe 240 can be disengaged from the guide structure by unscrewing thefour screws 306 so that the stop 262 is no longer attached to the bottombracket 250, thereby allowing the frame 240 to be displaced beyond the“open” position.

With reference to FIGS. 7A-7F, an embodiment of a entry/exit portmagazine 310 that is capable of holding a plurality of LTO tapecartridges and being engaged/disengaged to/from the magazine frame 240of the entry/exit port 104 is described. The magazine 310 is comprisedof a cartridge holding portion 312 and a dust cover 314.

The cartridge holding portion 312 is comprised of a bottom wall 316 anda side wall 318 that extends from the bottom wall 316 to a side walledge 320, which defines the opening through which an LTO cartridge isinserted/extracted into/from the magazine 310. The side wall 318 iscomprised of first and second end walls 322A, 322B and first and secondside walls 324A, 324B.

Respectively associated with the first and second side walls 324A, 324Bare first and second frame engagement structures 326A, 326B. The firstframe engagement structure 326A is comprised of a first substantiallyrigid flange 328A that extends outward from the first side wall 324A anda first pair of ribs 330A, 332A. Similarly, the second frame engagementstructure 326B is comprised of a substantially rigid flange 328B thatextends outward from the second side wall 324B and a second pair of ribs330B, 332B. The first substantially rigid flange 328A comprises a firstengagement surface 334A that is located at a first distance from theedge 320. Similarly, the second substantially rigid flange 328Bcomprises a second engagement surface 334B that is also located at thefirst distance from the edge 320. The bottom edges of the first pair ofribs 330A, 332A and second pair of 330B, 332B are each located at asecond distance from the edge 320 that is less than the first distance.The difference between the first and second distances is slightlygreater than the thickness of the material in which the first and secondflange engagement structures 268A, 268B have been established.

To engage the magazine 310 to the frame 240 of the entry/exit port 104(assuming the port is in the “open” position), the magazine is insertedinto the receptacle 264 such that the substantially rigid flanges 328A,328B are respectively pass through the wider openings located towardsthe top ends of the first and second flange engagement structures 268A,268B. The first pair of ribs 330A, 332A and the second pair of ribs330B, 332B respectively engage the back side bracket 254 and the frontside bracket 252 to limit the extent to which the flanges 328A, 328B canpass through the larger portions of the first and second flangeengagement structures 268A, 268B. At this point, the magazine 310 isdisplaced towards the bottom bracket 250 so that the first engagementsurface 334A of the first flange 328A engages the posterior side of theback side bracket 254 and the second engagement surface 334B of thesecond flange 328B engages the posterior side of the front side bracket252. At this point, the first engagement surface 334A is engaging theposterior side of the back side bracket 254 and the bottom edges of thefirst pair of ribs 330A, 332A are engaging the anterior surface of theback side bracket 254. Likewise, the second engagement surface 334B isengaging the posterior side of the front side bracket 252 and the secondpair of ribs 330B, 332B are engage the anterior surface of the frontside bracket 252. With the first and second engagement surfaces 334A,334B and the bottom edges of the first and second pairs of ribs 330A,332A, 330B, 332B engaged to the frame 240 in this manner, the positionof the magazine is substantially fixed in two orthogonal dimensions. Anend rib 334 associated with the first end wall 322A engages the bottombracket 250 to limit the extent to which the magazine 310 can bedisplaced towards the bottom bracket 250. To disengage the magazine 310from the frame 240 (still assuming the port 104 is in the “open”condition), the attachment operation is reversed, i.e., the magazine 310is displaced away from the bottom bracket 250 until the first and secondflanges can be pulled through the wider openings located towards the topends of the first and second flange engagement structures 268A, 268B todisengage the magazine 310 from the frame.

The first and second substantially rigid flanges 328A, 328B are alsolocated so as to establish an asymmetry that constrains the magazine 310to be mounted to the frame 240 in a single, preferred orientation. Toelaborate, the asymmetry is established by locating the first flange328A such that the flange is a first distance from the first end wall322A and locating the second flange 328B such that the flange is asecond distance from the second end wall 322B that is not equal to thefirst distance. In the illustrated embodiment, the first flange 328A islocated at a first distance from the first end wall 322A and a seconddistance from the second end wall 322B that is different than the firstdistance, and the second flange 328B is located the same second distancefrom the second end wall 322B. In addition, a cut-out 249 associatedwith the top guide channel 248 and the lack of a comparable cut-outassociated with the bottom bracket 252 prevent the magazine 310 frombeing mounted to the frame 240 in an undesired orientation.

Associated with the bottom wall 316 are a plurality of holes 336A-336Dthat are each engaged by a protrusion on the dust cover 314 of anothermagazine 310 to facilitate stacking of the magazines. There are numerousalternatives to the holes 336A-336D. Among the possible alternativesare: (a) one or more recesses that are each adapted to engage aprotrusion on the dust cover of another magazine; and (b) one or moreprotrusions that are each adapted to engage a hole on the dust cover ofanother magazine. Different numbers of structures can be utilized.Moreover, a structure with a different shape than the holes 336A-336D isalso feasible.

With reference to FIGS. 7A, 7B, and 7D, the dust cover 314 comprises anexterior surface 338 and an interior surface 340. Associated with theexterior surface are protrusions 342A-342D that are each capable ofmating with one of the plurality of holes 336A-336D associated withanother magazine to facilitate stacking of the magazines. There arenumerous alternative structures to the protrusions 342A-342D that can beused to facilitate stacking of magazines. For instances, holes orrecesses that mate with protrusions located on the bottom wall of amagazine can be used in place of the protrusions 342A-342D. Differentnumbers of structures and/or structures with different shapes from thoseillustrated can also be utilized.

Associated with the interior surface 340 of the cover 314 are a firstpair of detents 344A, 344B and a second pair of detents 346A, 346B thatare used to fasten the cover 314 to the cartridge holding portion 312.To elaborate, the first pair of detents 344A, 344B are adapted to engagea portion of a lip that is associated with the edge 320 and that islocated adjacent to first flange 328A, and the second pair of detents346A, 346B are adapted to engage a portion of the lip that is locatedadjacent to the second flange 328B. A pair of tabs 348A, 348B allow auser to disengage the cover 314 from the cartridge holding portion 312.To elaborate, the first tab 348A allows a user to flex the cover 314(which is preferably made of plastic) adjacent to the first pair ofdetents 344A, 344B in a manner that disengages the first pair of detents344A, 344B from the lip. The second tab 348B similarly allows a user todisengage the second pair of detents 346A, 346B from the lip.

Respectively associated with the first and second end walls 322A, 322Bare first and second bar code areas 350A, 350B that are each capable ofaccommodating a bar code. In many cases, the bar code is imprinted on alabel that is placed in the bar code area. In some embodiments, a singlebar code area that is associated with one of the first and second endwalls 322A, 322B or one of the first and second side walls 324A, 324B isadequate. In other embodiments, two or more bar codes areas, eachassociated with one of the first and second end walls 322A, 322B and thefirst and second side walls 324A, 324B is needed or desirable.

Extending from the second end wall 322B is a third bar code area 350C,which is shown with a bar code label attached. The third bar code areais located so that when the magazine 310 is within the library, themagazine can be identified. To elaborate, when the magazine 310 isattached to the magazine frame 240, any bar codes associated with thefirst and second bar code areas 350A, 350B or associated with any otherlocations on the side wall 318 are likely to be difficult for a bar codereader associated with the transport system 112 to read. In contrast, abar code associated with the third bar code area 350C is readily visibleto such a bar code reader. Generally, any bar code associated with thethird bar code area 350C is identical to the bar code associated withthe first and second bar code areas 350A, 350B. However, it is notrequired that a bar code associated with an individual magazine beidentical to any other bar codes associated with the magazine.

With reference to FIGS. 7E and 7F, the bottom wall 316, the first andsecond end walls 322A, 322B, the first and second side walls 324A, 324Bdefine an interior space that is capable of accommodating a plurality ofthe LTO tape cartridges. In the illustrated embodiment, three LTOcartridges are shown located within the interior space of the magazine310. A plurality of partition structures 352 divide the interior spaceinto a plurality of data cartridge storage spaces 354, each beingcapable of accommodating a single LTO tape cartridge. Each partition 352is comprised of a pair of panels 356A, 356B and a pair of spacer ribs358A, 358B. The spacer ribs 358A, 358B serve to space cartridges thatare stored in adjacent storage spaces a sufficient distance from oneanother so that the picker associated with the transport assembly cangrasp one of the cartridges without interference from any adjacentcartridges. Associated with each of the storage space 354 is a pair ofcentering fins 360A, 360B that serve to center a data cartridge withinthe storage space.

Also associated with each storage space 354 is an orientation structure362 that prevents insertion of an LTO tape cartridge into space if thecartridge does not have the proper orientation. To elaborate, theorientation structure 362 is designed to accommodate or complement theorientation feature 138 of an LTO tape cartridge that is being insertedinto the space and has the desired orientation. If, however, an LTO tapecartridge is being inserted into the space and does not have the desiredorientation, the orientation structure 362 is not positioned toaccommodate the orientation feature 138 of the LTO tape cartridge and,as such, interferes with the insertion of the LTO tape cartridge intothe space. Further, all of the orientation structures 362 in themagazine 310 are substantially identical to one another and insubstantially the same location in each storage space. Consequently, theorientation structures cumulatively operate to ensure that all of thecartridges that can be held by the magazine have the same orientationwithin the magazine. This characteristic of the magazine, in combinationwith the features of the magazine that require the magazine to be in aspecific orientation for attachment to the magazine frame 240 of theentry/exit port 104, ensure that all of the data cartridge that areplaced in the library via the entry/exit port 104 have the sameorientation relative to the picker, which facilitates the design of thepicker.

Additionally, a retaining structure 364 is associated with each of thestorage spaces 354 to prevent unintentional dislodgement of an LTOcartridge located in the space. Generally, the retaining structurecomprises a cantilever member with one end fixed to the cartridgeholding portion 312 and a free or movable end that supports a detent forengaging the notch 142B of an LTO cartridge. In operation, the springforce provided by the cantilever member urges the detent into engagementwith the notch 142B during insertion of the LTO cartridge into thecartridge holding portion 312 and allows the detent to disengage fromthe notch during extraction of the cartridge by a picker or user.

Each of the storage spaces 354 also comprises portions of stand-offs366A, 366B that ensure that the cartridge end 136A of the LTO cartridgeis substantially the same distance from the bottom wall of the 316 ofthe magazine 310 as the cartridge end 156A of a DLT tape cartridge isfrom the bottom wall of a magazine designed to accommodate DLT tapecartridges. In libraries that are capable of operating on cartridgeswith different dimensions, such as library 100, the use of stand-offs toensure this consistency of cartridge location simplifies the pickerdesign.

Associated with the side wall 324A are two orientation surfaces 368A,368B that can each be used by a picker to locate the data cartridgestorage spaces 354. The cover 314 is designed to accommodate theorientation surfaces 368A, 368B.

Associated with the side wall 324B are blockers 369A, 369B that serve toprevent the magazine frame 240 of the entry/exit port 104 from reachingthe closed position, as shown in FIG. 1A, if the magazine 310 is notfully engaged to the frame 240.

Associated with one of the partitions 352 is a strut 370 that connectsthe pair of panels 356A, 356B. The strut 370 prevents the first andsecond side walls 324A, 324B from bowing towards or away from oneanother. A picker space 372 associated with the storage space 254immediately adjacent to the first end wall 322 provides space that isutilized by a picker in inserting a data cartridge into the space 254and retracting a data cartridge from the space 254.

With reference to FIGS. 2 and 8A-8E, the magazine structure 106comprises first and second banks of magazines 380A, 380B. The first bankof magazines 380A is described with the understanding that the secondbank of magazines 380B (other than accommodating the entry/exit port104) is substantially identical. The first bank of magazines 380A iscomprised of four, multi-piece magazines 382A-382D. With reference toFIG. 8A, each of the multi-piece magazines 328A-382D is comprised of aback side 384, a first side 386A, and a second side 386B thatcumulatively define an interior space for accommodating a plurality ofdata cartridges and an opening through which data cartridges can beinserted/extracted into/from the interior space. Each of the multi-piecemagazines 382A-382D also comprises a partitioning structure 388 thatdivides the interior space into a plurality of storage spaces that areeach capable of accommodating an LTO tape data cartridge.

With reference to FIGS. 8A-8E, each of the multi-piece magazines382A-382D is comprised of a C-channel 390 and at least one magazine clip392. The C-channel 390 forms substantially the entire back side 384 ofthe magazine and portions of the first and second sides 386A, 386B ofthe magazine. The C-channel 390 comprises first and second C-channelsides 394A, 394B and a C-channel mid-section 396 that extends betweenand connects the first and second C-channel sides 394A, 394B. TheC-channel mid-section 396 forms substantially the entire back side 384of the magazine. In addition, the C-channel mid-section 396 comprises aplurality of stand-offs 398, with each stand-off positioned to engage atleast one LTO tape cartridge located in one of the storage spacesprovided by the magazine such that the cartridge end 136A of the LTOcartridge is substantially the same distance from the back side 384 asthe cartridge end 156A of a DLT tape cartridge is from the back side 384of a magazine designed to accommodate DLT tape cartridges. In librariesthat are capable of operating on cartridges with different dimensions,such as library 100, the use of stand-offs to ensure this consistency ofcartridge location simplifies the picker design. The C-channelmid-section 396 further comprises a plurality of rivet holes 400 thatallow the C-channel 390 to be attached to the top tray 182, bottom tray186, and exterior skins 178A, 178B by rivets. The C-channel 390, inconnecting the top tray 182 and the bottom 186 to one another, alsoprovides structural support that is not provided by the exterior skins178A, 178B. Consequently, each of the C-channels forms a structuralportion the frame 102.

Respectively associated with the first and second C-channel sides 394A,394B are first latch elements 402A, 402B that each form a latch with asecond latch element associated with the magazine clip 392 to join themagazine clip and the C-channel 390. In the illustrated embodiment, thefirst latch elements 402A-402B are holes. However, other types of latchelements are feasible. A plurality of slits 404 are also associated witheach of the first and second C-channel sides 394A, 394B. The slits 404cooperate with slot defining structures that are associated with themagazine clip 392 to further fix the magazine clip 292 to the C-channel390 in the manner that slotted cards are interconnected to build a houseof cards.

The C-channel 390 is preferably made of a metal (aluminum, sheet steeletc.). Further, the C-channel of each of the magazines in the first bankof magazines 380A forms a portion of the frame 102 of the library 101.This is also the case with respect to the second bank of magazines 380Bwith the possible exception of the magazine situation above theentry/exit port 104.

The magazine clip 392 is comprised of a side wall 406 that extends froma bottom edge 408 to a top edge 410 that defines an opening throughwhich an LTO cartridge is inserted/extracted into/from the magazine whenthe magazine clip 392 is joined to the C-channel 390. The side wall 406is comprised of first and second end walls 412A, 412B and first andsecond side walls 414A, 414B. Associated with the first and second sidewalls 414A, 414B are second latch elements 416A-416B that respectivelycooperate with first latch elements 402A-402B of the C-channel 390 toconnect the magazine clip 392 and the C-channel 390. In the illustratedembodiment, the second latch elements 416A-416B are each substantiallyrigid flanges. In joining the magazine clip 392 to the C-channel 390,the magazine clip 392 are brought together such that the second latchelements 416A, 416B cause the first and second C-channel sides 394A,394B to flex or spread apart. Once, however, the second latch elements416A, 416B reach the first latch elements 402A, 402B, the first andsecond C-channel side 394A, 394B come together to latch the magazineclip 392 and the C-channel 390.

Also associated with the first and second side walls 414A, 414B are slotdefining structures 418 that are each adapted to engage one of the slits404 associated with the first and second C-channel sides 394A, 394B. Theslot defining structures 418 and slits 404 operate to prevent themagazine clip 392 from being displaced towards the top tray 182 or thebottom tray 186.

The magazine clip 392 further comprises a plurality of partitions 420that define a plurality of LTO tape cartridge storage spaces 422. Eachof the partitions 420 is comprised of a panel 424, pair of spacer ribs426A, 426B that are each substantially identical to the comparableelement associated with the entry/exit port magazine 310 and performsubstantially the same function as the comparable element of theentry/exit port magazine 310. As such, these elements will not bedescribed further. Associated with each of the storage spaces 422 arecentering fins 428A, 428B and a retaining structure 430, which are eachsubstantially identical to the comparable element associated with theentry/exit port magazine 310 and perform substantially the same functionas the comparable element in the magazine 310. Consequently, thesefeatures will not be described further.

Notably, the magazine clip 392 does not include any kind of orientationfeature for ensuring that cartridges held by the magazine have apredetermined orientation. The magazine clip 392 lacks an orientationfeature because it is assumed that substantially all of the datacartridges that will be held by any one of the magazine associated withthe first and second banks of magazines 380A, 380B will enter thelibrary via the entry/exit port 104 and, as such, will have the desiredpredetermined orientation due to the operation of the entry/exit port104 and the entry/exit port magazine 310.

The magazine clip 392 also does not have any kind of back wall orstand-off feature like the entry/exit port magazine 310, nor does itneed any of these features because these features are provided by theC-channel 390. Consequently, absent the operation of the retainingstructure 430 associated with each data cartridge storage space of themagazine clip 392 and the attachment of the clip 392 to the C-channel390, a data cartridge can be passed all the way through the magazineclip 392. For example, a data cartridge could be inserted into themagazine clip 392 through the opening defined by the top edge 410 and,absent the operation of the retaining structure, be extracted through anopening defined, at least in part by the bottom edge 408.

The magazine clip 392 is made of one of the same class of materials asis used to make the cartridge housing of a data cartridge. Consequently,at present, the magazine clip 392 is made of plastic. The use of plasticto make the magazine clip 392 results in less wear and tear on thecartridge housings over numerous insertions and extractions relative toa clip made of, for example, metal.

For cartridges with dimensions that would place the cartridge end at adifferent distance from the back side 384 of a magazine designed toaccommodate LTO cartridges, such as magazine 382A, there are at leasttwo possible ways to design the magazine so that the cartridge will beat the same distance from the back side and thereby facilitate thepicker design. First, a shim can be attached to the stand-offs 398.Second, the magazine clip can be designed to hold the cartridge at thedesired distance.

It should be appreciated that a multi-piece magazine can be realized inwhich one piece forms at least a portion of the back of the magazinethat does not have a C-shape or U-shape. For example, a multi-piecemagazine can be realized in which a substantially flat piece of materialforms at least a portion of the back of the magazine. Additionally, amulti-piece magazine can be realized in which a piece that forms atleast a portion of the back of the magazine and a piece that forms atleast portions of the side are attached to one another in a manner thatdoes not involve overlapping side portions provided by each of thepieces. For example, the pieces can be joined to one another with aconnector that forms a butt joint between the pieces.

With reference to FIGS. 9A-9F, the drive bay 108 is comprised of a frame442 that defines a drive bay space which is capable of accommodating anumber of LTO drives that are each contained within a drive sled thatfacilitates hotswapping of drives to and from the library 100. The frame442 defines a first opening 444 (see FIG. 2) that exposes any drivesappropriately located in the drive bay 108 so to the transport system112 can load and unload tape cartridges from the drive. The frame 442also defines a second opening 446 that allows a user to insert andremove drives from the drive bay space.

With reference to FIG. 9B, which is a cross-sectional view of the drivebay 108, the drive bay 108 is further comprised of five fixed-partitions448A-448E that divide the drive bay space into six, full-height drivespaces 450A-450F, each capable of accommodating a full-height LTO drivelocated in a drive sled. The portion of the frame 442 adjacent to eachof the full-height drive spaces 450A-450F defines a pair of slots 452A,452B that are capable of engaging an insertable/removable partition 454.If the partition 454 engages one of the pair of slots 452A, 452B, thefull-height drive space with which the pair of slots is associated isdivided into two, half-height drive spaces 456A, 456B, each capable ofaccommodating a half-height drive located within a drive sled.Consequently, the drive bay 108 can be configured to provide twelvehalf-height drive spaces. However, because of the operation of thetransport assembly 112, the upper-most and lower-most half-height drivespaces cannot be utilized. As a consequence, only the middle ten of thetwelve possible half-height drive spaces can be utilized. In librariesthat employ different transport assemblies and/or have differentdimensions, this constraint on the number of half-height drives may notbe present and, as such, all of the possible half-height drive spaceswill be capable of being utilized.

Associated with each of the full-height drive spaces 450A-450F are firstand second plugs 458A, 458B that are used to provide power andintra-library control via a controller area network (CAN) to afull-height drive located in the space. If a full-height drive space isdivided into two, half-height drive spaces, the first plug 458A is usedto provide power to any half-height drive located in the half-heightdrive space 456A (i.e., the upper, half-height drive space) and thesecond plug 458B is used to provide power to any half-height drivelocated in the half-height drive space 456B (i.e., the lower,half-height drive space).

As should be appreciated, the drive bay 108 is capable of accommodatingonly full-height drives, only half-height drives, combinations offull-height and half-height drives, and less than a full complement ofdrives. For example, FIG. 9C shows the drive bay 108 configured suchthat the full-height drive space 450B has been partitioned into two,half-height drive spaces with one space containing a half-height driveand the other space containing a half-height drive block-off plate; afull-height drive in full-height drive space 450F; and full-height driveblock-off plates 460 in each of full-height drives spaces 450A, 450C,450D and 450E.

FIGS. 9D-9F illustrate a drive sled 470 for housing a full-height LTOtape drive 472. The LTO tape drive 472 is shown with an LTO tapecartridge 474 inserted in the receptacle of the drive. The drive sled470 generally facilitates the insertion/removal of a drive into/from thedrive bay 108 via the second open side 446 of the drive bay 108. Morespecifically, the drive sled 470 facilitates insertion of a drive byallowing a power connection to be established between the drive and oneof the plugs 458A, 458B by inserting the drive and the sled into one ofthe full-height drive spaces 450A-450F. The drive sled 470 facilitatesremoval of a drive by allowing a power connection between a drive andone of the plugs 458A, 458B to be terminated by extracting the sled fromthe full-height drive space 450A-450F in which the drive and sled areresident.

The sled 470 comprises a housing 476 with a front side 478A, back side478B, first lateral side 478C, second lateral side 478D, top side 478Eand bottom side 478F. Associated with the front side 478A are first andsecond plug receptacles 480A, 480B that are adapted to engage the plugs458A, 458B associated with a full-height drive space within the drivebay 108.

Associated with the back side 478B of the housing are a pair of SCSIconnectors 484A, 484B that are respectively used to establish a “daisychain” connection to a SCSI cable over which SCSI commands and data aretransmitted to/from drives resident in the drive bay 108. Alsoassociated with the back side 478B are: (a) a latch 486 that is used toretain the sled with a drive bay; (b) a handle 488 that facilitates theinsertion and extraction of the sled 470 from the drive bay 108; (c) agrill 490 for moving air from the interior of the sled 470 to theexterior environment and thereby contribute to the cooling of any driveresident in the sled; and (d) an LED 491 that is used to provide a userwith an indication of the operational status of any drive resident inthe sled.

Associated with the first lateral side 478C of the sled 470 is a springlatch 492 that is activated by the latch 486 and cooperates with theframe 442 of the drive bay 108 to retain the sled within one of thedrive storage spaces. The first lateral side 478C also comprises a pairof mounting holes 494A, 494B that each receive a screw that, in turn,engages a threaded hole associated with the housing of a drive to fixthe drive within the sled. Similarly, the second lateral side 478Dcomprises mounting holes 496A, 496B that each receive a screw that, inturn, engages a threaded hole associated with the housing of a drive tofix the drive within the sled.

The top side 478E can be detached from the remainder of the housing 476so that a drive can be inserted/extracted into/from the interior of thesled 470. The top side 478E is detached by removing a screw 498 andsliding the top side 478E (which is captured by overlying flanges500A-500D and underlying flanges 502A-502F extending from the first andsecond lateral sides) rearward.

With reference to FIG. 9F, the sled 470 comprises a fan 504 thatoperates to move air from the interior of the sled to the exteriorenvironment via the grill 490. The sled further comprises a powerdistribution device 506 that distributes power received via one of thefirst and second receptacles 480A, 480B to the fan 504 and to any driveresident in the sled via a drive power connector 508. The powerconnector 508 is used to establish an electrical connection with thedrive via a power cable that extends between the connector 508 and apower connection interface associated with the drive. Similarly, theinterior sides of the SCSI connectors 484A, 484B are used to establishelectrical connection with the SCSI interface of the drive via a SCSIcable.

A half-height sled has substantially the same structure as thefull-height sled 470. However, the half-height sled has only one plugreceptacle for receiving power from one of the plugs 458A, 458Bassociated with a half-height drive space.

With reference to FIGS. 10A-10B, the power supply/control module bay 114is comprised of a frame 520 that defines an interior space thataccommodates a library control module and a maximum of two powersupplies. Generally, the frame 520 is comprised of a portion of theframe 442 of the drive bay 108, a portion of the top tray 182, a sectionof the side portion 180B, a section of the side portion 184B, a portionof the bottom tray 186, a divider 522, and exterior wall 524. Theexterior wall 524 defines a library control module opening 526 forinsertion/extraction of a library control module into/from the interiorspace; a power supply opening 528 for the insertion/extraction of powersupplies into/from the interior space; and plug receptacle opening 530for accommodating the plug receptacles that receive the AC power plugsthat are used to provide the power used by any power supplies in theinterior space.

The bay 114 further comprises a library control module cage 532 forreceiving a library control module that is used to distribute power toother elements within the library 100 and control the operation of thelibrary 100. Also comprising the bay 114 is a power supply cage 534 thatis capable of accommodating two power supplies. The library 100 onlyrequires one power supply to operate. Nonetheless, the bay 114 is ableto accommodate two power supplies so that there is a back-up powersupply available and on-line should one of the two, power supplies fail,thereby enhancing the reliability of the library 100.

FIG. 10B illustrate the power supply/library control module bay 114fully populated, i.e. with a library control module 536 situated in thelibrary control module cage 532 and first and second power supplies538A, 538B located in the power supply cage 534. In addition, plugreceptacles 540A, 540B are located in the plug receptacle opening 530.

With reference to FIGS. 11A-11C, the universal bay 120 is generally foraccommodating electronic or processing circuitry that can enhance orsupplement the operation of the library 100 but is not electronic orprocessing circuitry that is necessary to the operation of the library,such necessary circuitry being located in the power supply/librarycontrol module bay 114 or elsewhere. It should also be noted that theuniversal bay 120 is located in a space that is separate from the spacesdedicated to the storage of data cartridges (including the entry/exitport 104); drives; the transport of data cartridges between the spacefor storing data cartridges the drives, power supply, and controlsystems necessary to the operation of the library 100. Moreover, spacewithin the universal bay 120 is not accessible to the transport system112.

The universal bay 120 is comprised of a frame 550 that defines aninterior space that accommodates enhancing or supplementing circuitry.Generally, the frame 550 is comprised of a portion of the frame 442 ofthe drive bay 108, a portion of the top tray 182, a section of the sideportion 180A, a section of the side portion 184A, a portion of thebottom tray 186, and a divider 552. The frame also comprises an exteriorwall 554 defines one or more openings that are adapted to receive thedesired electronics. Since the desired electronics may be in a number ofdifferent forms the number of holes, the location of any holes, and thedimensions of any holes associated with the exterior wall 554 varydepending on the desired electronics. In the illustrated embodiment, theexterior 554 defines the openings needed for a quad-interface process(QIP) and a card cage that can be used to accommodate the cards neededto realize a PC or other device within the library 100. A QIP is adevice that is capable of processing, relative to the drives within thelibrary 100, SCSI data and command signals associated with four SCSIbusses. Normally, the QIP operates with respect to four, full-heightdrives but is capable of operating with eight, half-height drives.

Further comprising the universal bay 120 is a partition 556 that dividesthe interior space of the universal bay 120 into first and second spaces558A, 558B. The partition 556 is removable. Consequently, should a userwant to use more space than either the first space 558A or the secondspace 558B can provide, a greater amount of space is available. Itshould also be appreciated that partition structures are feasible thatdivide the interior space into a greater number of subsidiary spaces andinto spaces with different dimension than those shown.

Associated with the first space 558A is a first circuit board 560A thatis operatively attached to the divider 552 and adapted to engage theinterface of whatever type of circuitry is located in the first space558A. Similarly, a second circuit board 560B is associated with thesecond space 558B. The second circuit board 560B is operatively attachedto the divider 552 and adapted to engage the interface of whatever typeof circuitry is located in the second space 558B. If the partition 556is removed or never installed to realize a space that is bigger thanthat provided by either of the first and second space 558A, 558B, one ormore circuit boards are attached to the divider 552 and adapted toengage the interface of whatever circuitry the user chooses to locate inthe space.

When the interior space of the universal bay 120 is divided into thefirst and second spaces 558A, 558B, there are presently the options of:(a) placing a QIP in one or both of the spaces; (b) placing a 3 U highCPCI card cage in one or both of the spaces; and (c) placing a 6 U highcard cage in the second space 558B, which is taller than the first space558A. Presently, when the interior space of the universal bay 120 isundivided, the space is capable of supporting a two high, 6 U card cage.For example and with reference to FIG. 11B, the universal bay 120comprises a 3 U card cage 562 located in the first space 558A and a QIPcage 564 located in the second space 558B. FIG. 11C illustrates the 3 Ucard cage 562 populated with CPCI cards 566, and the QIP cage 564housing a QIP 568. As should be appreciated, the use of the interiorspace within the universal bay 120 is not limited to the optionsdescribed above.

It should be appreciated that the configuration and any reconfigurationof the drive bay 108 with drives and/or configuration or reconfigurationof the universal bay 120 can be accomplished entirely from the rear side170B of the library 100, thereby avoiding any need to remove the library100 from an equipment rack.

With reference to FIGS. 12A-12E, the transport system 112 is comprisedof: (a) a picker 580 that is capable of grasping a data cartridge thatis located in a storage space associated with the entry/exit port 104,magazine structure 106, any one of the drives located in the drive bay108 and displacing a grasped data cartridge towards or away from astorage space; and (b) an elevator 582 that moves the picker 580 withinthe library 100 so that the picker 580 can perform the noted graspingand displacing operations. Due to the layout of the entry/exit port 104,the magazine structure 106 and the drive bay 108 and the need for theelevator to move the picker between each space associated with theentry/exit port 104, magazine structure 106 and the drive bay 108, theelevator 582 is capable of vertical and horizontal displacement of thepicker 580, as well as rotation of the picker 580 about a vertical axis.

The elevator 582 comprises a picker carriage 584 that supports thepicker 580. The carriage 584 is comprised of a vertical member 586, atop bracket 588 that is connected to one end of the vertical member 586,and a bottom bracket 590 that is connected to the other end of thevertical member 586.

Associated with the carriage 584 is a vertical displacement system 592for vertically displacing to the picker 580 to a desired locationbetween the top bracket 588 and the bottom bracket 590. The verticaldisplacement system 592 is comprised of: (a) a vertical linear rail 594that is adapted to engage linear rail mounts associated with the picker580 to guide the picker 580; (b) a vertical drive system 596 forproviding the motive force to move the picker 580 to a desired locationalong the linear rail 594; and (c) a vertical position sensor system 598for determining the location of the picker 580 along the linear rail594.

The vertical drive system 596 is comprised of: (a) a lead screw 600 withfirst and second ends that respectively journaled to the top bracket 588and the bottom bracket 590; (b) a lead screw pulley 602 that is attachedto the lead screw 600; (c) a stepper motor 604; (d) a spindle pulley 606that is attached to the spindle of the stepper motor 604; and (e) atiming belt 608 that connects the lead screw pulley 602 and the spindlepulley 606.

The vertical position sensor system 598 is comprised of: (a) a homesensor 610 that detects when the picker 580 is at a “home” position,which in this embodiment is adjacent to the bottom bracket 590; and (b)an encoder bar 612 that extends between the top bracket 588 and bottombracket 590 and is used to determine the location of the picker 580relative to the “home” position. Also associated with the verticalposition sensor system 598 is a sensor that cooperates with the encoderbar 612 to provide information on the vertical position of the picker580 relative to the “home” position.

Operation of the vertical displacement system 592 comprises using thestepper motor 604 to drive the lead screw 600 in either a clockwisedirection to cause the picker 580 to be displaced along the linear rail594 and towards the top bracket 588 or a counter-clockwise direction tocause the picker 580 to be displaced along the linear rail 594 andtowards the bottom bracket 590. The vertical sensor system 592 is usedto control the stepper motor 604 so that the stepper motor 604 isoperated to position the picker 580 at the desired vertical location.

To rotate the picker 580, the transport system further comprises arotational displacement system 620 that is used to rotate the pickercarriage 584 and, as a consequence, the picker 580. The rotationaldisplacement system 620 comprises: (a) a top plate 622 and bottom plate624 that are respectively journaled to the top bracket 588 and thebottom bracket 590 of the carriage 584 to guide the rotational movementof the carriage 584; (b) a rotational drive system 626 for providing themotive force to rotate the carriage 586 and the picker 580 to a desiredrotational position relative to the top plate 622 and the bottom plate624; and (c) a rotational position sensor system 628 for determining therotational position of the carriage 584 and the picker 580. Therotational displacement system 620 further comprises a limiting system630 for limiting the range of rotation of the carriage 584 and thepicker 580.

The rotational drive system 626 comprises: (a) a stepper motor 632 thatprovides the motive force for rotating the carriage 584 and the picker580 relative to the top plate 622 and bottom plate 624; (b) a sectorgear 634 that is operatively attached to the bottom plate 624; (c) apinion 636 that is operatively attached to the spindle of the steppermotor 632; and (d) a cluster gear 638 that is operatively attached tothe bottom bracket 590 of the carriage 584 and that operates to transfera rotational force from the pinion 636 to the sector gear 634.

The rotational position sensor system 628 comprises: (a) a flag 640 thatis operatively attached to the bottom bracket 590 of the carriage 584;and (b) a detector 642 that operates to detect the flag 640 and therebyprovide an indication of when the carriage 584 and picker 580 are at a“home” rotational position. Once the “home” position is detected usingthe flag 640 and the detector 642, the signals provided to the steppermotor to cause rotation of the carriage 584 and the picker 580 are alsoused to calculate the rotational position of the carriage 584 and thepicker 580 relative to the “home” position.

The limiting system 630 operates to limit the rotation of the carriage584 and the picker 580 to the approximately 180 degree range that isneeded to move data cartridges between any of the storage and drivespaces within the library 100 that are capable of accommodating a datacartridge. The limiting system 630 comprises: (a) first and second hardstops 644A, 644B that are operatively connected to the bottom plate 624;and (b) member 646 that is operatively connected to the bottom bracket590 of the carriage 584 and positioned to engage the first and secondhard stops 644A, 644B to prevent rotation of the carriage 584 beyond thedesired range.

Operation of the rotational displacement system 620 comprises using thestepper motor 632, pinion 636, cluster gear 638, and sector gear 634 torotate the carriage 584 in a clockwise or counter-clockwise direction.The rotational position sensor system 628 is used to control the steppermotor 632 so that the stepper motor 632 positions the picker 580 at thedesired rotational position. The limiting system 630 operates to limitthe range of rotational positions at which the rotational drive system626 can position the carriage 584 and picker 580.

The transport system further comprises a horizontal displacement system650 for horizontally translating the picker 580. The horizontaldisplacement system 650 comprises: (a) a top guide system 652 forhorizontally guiding the top bracket 588 of the carriage 584; (b) abottom guide system 654 for horizontally guiding the bottom bracket 590of the carriage 584; (c) a horizontal drive system 656 for providing themotive force to drive the carriage 586 and the picker 580 to a desiredhorizontal position; and (d) a horizontal position sensor system 658 fordetermining the horizontal position of the carriage 584 and the picker580.

The top guide system 652 is comprised of: (a) a pair of rails 660A, 660Bthat are attached to the top tray 182; and (b) a roller system 662 thatis comprised of a plate 664 that is fixed to the top plate 622 of therotational displacement system 620 and a pair of rollers 666A, 666B thateach engage the rails 660A, 660B. Each of the rollers 666A, 666B ispivotally attached to the plate 664.

The bottom guide system 654 is comprised of: (a) a horizontal linearrail 668 that is operatively attached to robotics module tray 670; and(b) a pair of linear rail mounts (not shown) that are operativelyattached to the bottom plate 624 of the rotational displacement systemand engage the horizontal linear rail 668.

The horizontal drive system 656 is comprised of: (a) a stepper motor 672that is attached to the robotic module tray 670 and provides the motiveforce for horizontally displacing the carriage 584 and the picker 580that is attached to the carriage; (b) a bottom drive system 674 forapplying a motive force to the bottom plate 624; (c) a top drive system676 for applying a motive force to the top plate 622; and (d) a shaft678 for transmitting a motive force from the bottom drive system 674 tothe top drive system 676.

The bottom drive system 674 is comprised of: (a) drive pulley 680 thatis attached to the spindle of the stepper motor 672; (b) a clusterpulley 682 that is operatively attached to the tray 670; (c) a firstshaft pulley 684 that is also operatively attached to the tray 670; (d)a first timing belt 686 that extends between the drive pulley 680 andthe cluster pulley 682; (e) a second timing belt 688 that extendsbetween the cluster pulley 682 and the first shaft pulley 684; and (f) aconnecting bracket 690 that connects the second timing belt 688 to thebottom plate 624. The connecting bracket 690 also incorporates a devicefor tensioning the second timing belt 688. Alternatively, tensioning ofthe second timing belt 688 can be accomplished by providing a structurefor adjusting the position of at least one of the cluster pulley 682 andthe first shaft pulley 684.

The top drive system 676 is comprised of: (a) pulley 692 that isattached to the top tray 182 via a bracket 694; (b) a second shaftpulley 696 that is attached to the top tray 182 via a bracket 698; (c) athird timing belt 700 that extends between the pulley 692 and the secondshaft pulley 696; and (d) a connecting bracket 701 that connects thethird timing belt 700 to the top plate 622. The connecting bracket 701also incorporates a device for tensioning the third timing belt 700. Ascrew connection 701A allows the plate 664 to be quickly disconnectedfrom the top plate 622.

The shaft 678 comprises: (a) a first shaft piece 702 that is operativelyconnected to the cluster pulley 682; (b) a second shaft piece 704 thatis operatively connected to the second shaft pulley 692; and (c) aconnector 706 that is used to connect the first shaft piece 702 and thesecond shaft piece 704. The connector 706 comprises a first spline thatis associated with the first shaft piece 702, a second spline that isassociated with the second shaft piece 704, and a spline sleeve 708 thatis attached to the second shaft piece 704. The spline sleeve 708, as aresult of its engagement with the second spline, is constrained suchthat it is not able to rotate about the second shaft piece 704 but iscapable of being linearly displaced to engage and disengage the firstshaft piece 702 and the second shaft piece 704. To elaborate, by slidingthe spline sleeve 708 towards the first shaft 702, the spline sleeve 708engages the spline of the first shaft piece 702 to connect the firstshaft piece 702 and the second shaft piece 704. Conversely, by slidingthe spline sleeve 708 away from the first shaft 702, the spline sleeve708 disengages from the spline of the first shaft piece 702 to disengagethe first shaft piece 702 and the second shaft piece 704. A collaredspring structure 710 is used to bias the spline sleeve 708 towardsengagement with the first shaft piece 702. Other biasing devices arefeasible. Other coupling devices are also feasible. For example, thefirst shaft piece 702 and the second shaft piece 704 can be connected toone another and disconnected from one another using a clamping shaftcoupler that utilizes a screw to adjust the diameter of a collar toengage or disengage the shaft pieces.

The horizontal position sensor system 658 comprises: (a) a home sensor712 for sensing when the carriage 584 and the picker 580 are at ahorizontal “home” position from which other horizontal positions can bedetermined; (b) a coarse horizontal position sensor 714 for determiningthe coarse position of the carriage 584 and the picker 580; and (c) afine horizontal position sensor 716. The coarse horizontal positionsensor 714 comprises a coarse flag 718 that is operatively attached tothe tray 670 and a coarse detector 720 that is operatively attached tothe bottom plate 624 and that cooperates with the coarse flag 718 todetermine the half of the range of possible horizontal positions inwhich the carriage 584 and the picker 580 are located. The finehorizontal position sensor 716 comprises a fine, crenelated flag 722 anda fine detector 724 that is operatively attached to the bottom plate 624and that cooperates with the crenelated fine flag 722 to provide ahigher resolution determination of the location of the carriage 584 andthe picker 580 than provided by the coarse detector 720.

Operation of the horizontal displacement system 650 comprises using thestepper motor 672 to provide a motive force that is used to horizontallydisplace the carriage 584 and the picker 580 towards or away from thedrive bay 108 as constrained by the top guide system 652 and the bottomguide system 654. The motive force produced by the stepper motor 672 istransmitted to the carriage 584 via the bottom drive system 674, topdrive system 676, and shaft 678. The horizontal position sensor system658 is used to determine the current position of the carriage 584 andthe picker 580 relative to the “home” position.

With reference to FIGS. 14A-14F, the picker 580 is comprised of: (a) abase plate 800 that supports other elements of the picker; (b) a grasperassembly 802 that is capable of being placed in a “closed” state inwhich a data cartridge can be grasped and an “open” state in which adata cartridge can not be grasped; (c) a pusher plate assembly 804 thatsupports the grasper assembly 802 and is used in moving the grasperassembly towards and away from a location in which a data cartridge islocated or may be located; and (d) a crank assembly 806 that providesthe motive forces needed to place the grasper assembly 802 in the “open”or “closed” states and to move the pusher plate assembly 804.

In addition to supporting other elements of the picker, the base plate800 also supports elements of the vertical displacement system 592 thatare used to position the picker 580 at a desired vertical location.Specifically, the base plate 800 supports: (a) a pair of mounts 810A,810B that connect the base plate 800 to the vertical linear rail 594;(b) a lead screw nut 812 that receives the lead screw 600; and (c) avertical encoder sensor 814 that cooperates with the encoder bar 512 toprovide information that is used to determine the vertical position ofthe picker 580. Rotation of the lead screw 600 provides a motive forcethat is applied to the base plate 800 via the lead screw nut 812 to movethe base plate to a desired vertical location along the vertical linearrail 594.

The grasper assembly 802 is comprised of: (a) a static member 820 thathas a first surface 822 for engaging one side of a data cartridge; and(b) a moving member system 824 that has a second surface 826 forengaging the opposite side of a data cartridge. The moving member system824 is also capable of being moved between a “closed” position in whichthe second surface 826 and the first surface 822 are capable of graspinga data cartridge and an “open” position in which the second surface 826and the first surface 822 are not capable of grasping a data cartridge.The grasper assembly 802 is further comprised of a bias system 828 thatserves to bias the moving member system 824 such that the second surface826 is forced towards the “closed” position. Further comprising thegrasper assembly 802 is grasper cam follower 830 that interacts with agrasper cam driver associated with the crank assembly 106 to force themoving member 824 towards the “open” position. It should be appreciatedthat grasping assemblies in which two moving members are used to graspand release a data cartridge are also feasible. Further, graspingassemblies in which there is a bias system that biases one or moremembers that are used to grasp a data cartridge towards an “open”position are feasible. Similarly, grasper assemblies that employ agrasper cam follower that forces one or more member that are used tograsp a data cartridge towards a “closed” position are feasible.

The moving member system 824 is comprised of: (a) an upper jaw 836; (b)a jaw grip 838 that is attached to the upperjaw 836 and provides thesecond surface 826; (c) a mount 840; (d) a u-shaped linkage 842 thatextends between the mount 840 and the upper jaw 836; and (e) a link 844that also extends between the mount 840 and the upper jaw 836. The jawgrip 838 is typically made of rubber or some other material thatprovides a good grip. The u-shaped linkage 842 and the link 844 operateto constrain the movement of the upper jaw 836 so that the secondsurface 826 associated with the jaw grip 838 does not rotate about anaxis.

The bias system 828 is comprised of a spring 850 that is located withina hole 852 of a housing 854. One end of the spring 850 is locatedadjacent to a cover 856 that is attached to the housing 854. The otherend of the spring 850 contacts a surface associated with the upper jaw836. In operation, the spring 850 applies a force to the upper jaw 836such that the second surface 826 is forced towards the “closed”position. Other types of bias systems are also feasible.

The grasper cam follower 830 is operatively attached to the upper jaw836 and is comprised of a horizontal surface 860 and a transitionalsurface 862. The horizontal surface 860 interacts with the grasper camdriver associated with the crank assembly 806 to force the secondsurface 826 towards the “open” position, which is in opposition to theoperation of the bias system 828. The transitional surface 826 interactswith the grasper cam driver associated with the crank assembly 806 sothat there is a gradual transition of the second surface 826 between the“open” and “closed” positions.

Associated with the grasper assembly 802 is a “tape-in-jaw” sensingsystem 868 that is comprised of a flag assembly 870 and a sensor 872.The flag assembly 870 is comprised of a spring-loaded plunger assembly872. In operation, the plunger of the spring-loaded plunger 872 is in afirst position if the grasping assembly 802 is not grasping a datacartridge. If, however, the grasping assembly 802 is grasping a datacartridge, the plunger moves to a second position. When the pusher plateassembly is at or near a fully retracted position, the sensor 872 candetect whether the plunger is in the first position or the secondposition. This information is used to determine which direction a crankassociated with the crank assembly should be rotated. More specifically,if the grasper assembly 802 is grasping a data cartridge, the crank willbe rotated in whichever direction, clock-wise or counter clock-wise,will maintain the grip on the data cartridge. If, the grasper assembly802 is not grasping a data cartridge, the crank will be rotated in theopposite direction from that used to maintain a grip on a datacartridge.

The pusher plate assembly 804 is comprised of: (a) a first member 880that supports the gripper assembly 802 and comprises pusher plate camfollower; (b) an L-shaped member 882 that is operatively connected tothe first member 880; (c) a linear rail 884 that is operativelyconnected to the base plate 800; (d) a pair of mounts 886A, 886B thatconnect the L-shaped member 882 to the linear rail 884; and (e) a rollerassembly 888 that also connects the first member 880 to the base plate800 and allows the first member 880 to move relative to the base plate800. The linear rail 884 and pair of mounts 886A, 886B operate toconstrain the movement of the gripper assembly 802 to linear movementtowards and away from locations at which a data cartridge is located orcan be located. Other types of base plate assemblies that are capable ofbeing used to move a gripper assembly towards and away from locations atwhich a data cartridge is or can be located are feasible.

The first member 800 comprises a pusher cam follower surface 894 thatinteracts with a pusher plate cam driver associated with the crankassembly 806 to move the pusher plate assembly 804 to a desired locationalong the linear rail 884. Generally, the cam follower surface 894 iscomprised of two, parallel surfaces 896A, 896B. The application of aforce by the pusher plate cam driver to the surface 896A drives thepusher plate assembly 804 away from the elevator 582. Conversely, theapplication of a force by the pusher plate cam driver to the surface896B drives the pusher plate assembly 804 towards the elevator 582.Forming a portion of the surface 896A is a compliance member 898 thatflexes to reduce the force being applied by the pusher plate cam driverto a data cartridge that has been contacted by the grasper assembly 802.In the illustrated embodiment, the compliance member 898 is comprised ofa flat spring 900 that is located in a recess 902. One end of the spring900 is fixed to the first member 880 and the other end of the spring 900floats within the recess 902 to allow the spring 900 to flex. Forming aportion of the surface 896B is a dwell 904 that prevents the pusherplate cam driver from applying a force to the pusher plate assembly 804over the extent of the dwell 898.

The crank assembly 806 is comprised of: (a) a motor assembly 910 forproviding a rotational motive force; (b) a crank 912 for rotating aboutan axis 913 in response to the rotational motive force provided by themotor assembly; and (c) a camming structure 914 that provides a graspercam driver surface for interacting with a grasper cam follower and apusher plate cam driver surface for interacting with a pusher plate camfollower, and moves through the operation of the motor assembly 910 andthe crank 912.

The motor assembly 910 is comprised of: (a) a stepper motor 920 that isattached to the base plate 800; and (b) a pinion 922 that is attached tothe spindle of the stepper motor 920. The stepper motor 920 is capableof rotating the pinion 922 in a clock-wise direction and acounter-clockwise direction.

The crank 912 is comprised of: (a) a crank spindle 928 that is attachedto the base plate 800; (b) a crank top 930; (c) an inner gear 932 thatis attached to the crank top 930 and that engages the pinion 922 that isassociated with the stepper motor 920; and (d) a bearing assembly 934that connects the crank top 930 and the inner gear 932 to the spindle928.

The camming structure 914 is operatively attached to the crank top 930and is comprised of a cylindrical surface 940 and a spherical surface942. All or a substantial portion of the cylindrical surface 940 is thepusher plate cam driver surface that interacts with the pusher plate camfollower surface 894 to move the pusher plate assembly 804. Thecylindrical surface 940 has a surface vector that is substantiallyperpendicular to the axis 913. Pusher plate cam driver surfaces that areother than cylindrical surfaces are feasible provided the surface iscapable of interacting with a pusher plate cam follower surface to movethe pusher plate to the desired location. At least a portion of thespherical surface 942 is the grasper cam driver surface that interactswith the grasper cam follower 830 to force the second surface 826associated with the upper jaw 836 to move towards the “open” position.

Associated with the crank assembly 806 is a crank position sensingsystem 948 that is comprised of: (a) a 50/50 flag 950 that is attachedto the underside of the crank top 930 and used to determine whether thecrank 912 is within a first 180 degree range of operation or a second180 degree range of operation that does not substantially overlap withthe first 180 degree range of operation; (b) a 50/50 flag sensor 952 fordetecting the 50/50 flag; (c) a plurality of pins 954 that are attachedto the underside of the crank top 930 and used to determine where thecrank 912 is operating to a greater degree of accuracy than is possiblewith the 50/50 flag 950; and (d) an encoder sensor 956 for detectingpins associated with the plurality of pins 954.

Also associated with the picker 580 is a calibration sensor 962 that isused to orient and/or calibrate the positioning systems within thelibrary 100 by detecting the orientation structures 368A, 368Bassociated with the entry/exit port magazine 310, the top surfaces ofthe slit defining structures 418 of the magazines in the magazinestructure 106, and drive orientation structures associated 964 (see FIG.9B) with the frame 442 of the drive bay 108.

Further associated with the picker 580 is a bar code sensor 966 that isused to detect a bar code that is associated with an entry/exit portmagazine 310 and bar codes associated with data cartridges locatedwithin the library 100.

With reference to FIGS. 15A1-15D2, the operation of the picker 580 ingrasping an LTO data cartridge 980 is described. FIGS. 15A1 and 15A2illustrate the situation in which: (a) the picker 580 has beenpositioned adjacent to the data cartridge 980 that is to be grasped; and(b) the pusher plate assembly 804 is fully retracted, i.e., the crankassembly 806 has been used to position the pusher plate assembly 804 asclose to the elevator 582 as is possible. In this state, a portion ofthe spherical surface 942 is engaging the horizontal surface 860 of thegrasper cam follower 830. As a consequence, the moving member 824 ispositioned such that the second surface 826 and the first surface 822are in the “open” position, i.e., incapable of grasping a datacartridge. Further, the flag assembly 870 of the tape-in-jaw sensorysystem 868 is in a state that indicates that there is no tape locatedbetween the first surface 822 and the second surface 826.

FIGS. 15B1 and 15B2 illustrate the state of the picker 580 and the datacartridge 980 after the crank 912 has rotated the camming structure 914in a counter-clockwise direction 984 though about 180 degrees relativeto position of the camming structure 914 shown in FIGS. 15A1 and 15A2.The rotation of the camming structure 914 has caused the pusher platecam driver portion of the cylindrical surface 940 to apply a force tothe pusher cam follower surface 896A that has moved the pusher plateassembly 804 from the position shown in FIG. 15A 1 to the position shownin FIG. 15A 2. At this point, the spherical surface 942 is stillengaging the horizontal surface 860 of the grasper cam follower 830.Consequently, the first surface 822 and the second surface 826 of thegrasper assembly 802 are still in the “open” position. Since the datacartridge 980 is now in between the first surface 822 and the secondsurface 826, the flag assembly 870 is now in a state that indicates thiscondition. However, the flag assembly 870 is not yet positioned so thatthe plunger can be detected by the sensor 872.

FIGS. 15C1 and 15C2 illustrate the state of the picker 580 and the datacartridge 980 after the crank 912 has slightly further rotated thecamming structure 914 in the counter-clockwise direction 984 relative tothe rotational position of the camming structure 914 shown in FIGS. 15B1and 15B2. Due to the operation of the compliance member 898, the furtherrotation has resulted in little, if any, further linear displacement ofthe pusher plate assembly 804. The spherical surface 942 is, due to thefurther rotation, no longer in contact with the grasper cam follower830. As a consequence, the bias system 828 has caused the second surface826 to move towards the first surface 822 and the cartridge 980 to begrasped. The flag assembly 870 is still in a state that indicates that acartridge is located between the first surface 822 and the secondsurface 826. Further, the flag assembly 870 is still not positioned sothat the sensor 872 can detect the plunger associated with the assembly.

FIGS. 15D1 and 15D2 illustrate the state of the picker 580 and the datacartridge 980 after the crank 912 has further rotated the cammingstructure 914 in the counter-clockwise direction 984 through about 180degrees relative to position of the camming structure 914 shown in FIGS.15B1 and 15B2, i.e. almost back to the fully retracted position. Thefurther rotation of the camming structure 914 has caused the pusherplate cam driver portion of the cylindrical surface 940 to apply a forceto the pusher cam follower surface 896B that has moved the pusher plateassembly 804 from the position shown in FIG. 15B 1 to the position shownin FIG. 15D 2. The spherical surface 942 is still not in contact withthe grasper cam follower 830. As a consequence, the first surface 822and the second surface 826 are still grasping the cartridge 980. Theflag assembly 870 is still in a state that indicates that the cartridgeis located between the first surface 822 and the second surface 826.However, the plunger associated with the flag assembly 870 is nowpositioned so that the sensor 872 can detect the plunger. The facts thatthe sensor 872 has detected that the data cartridge 980 is locatedbetween the first surface 822 and the second surface 826 and that thepusher plate assembly 804 is at or near to the fully retracted positiondictate that any subsequent rotation of the crank 912 must be in theclockwise direction. Further rotation of the crank 912 in thecounter-clockwise direction would result in the second surface 826 beingdisplaced away from the first surface, which could result in thecartridge being dropped. Insertion of the grasped data cartridge into alocation that is capable of holding the cartridge is accomplished byreversing the noted operations, which involves clockwise rotation of thecrank 912.

It should be appreciated that the picker 580 operates such that: (a) fora first range of the rotation of the crank 912, the grasper assembly 802is in the open position and incapable of grasping a cartridge, and (b)for a second range of rotation of the crank 912 that does notsubstantially overlap with the first range, the grasper assembly 802 isin the closed position that allows a cartridge to be grasped. Withreference to FIGS. 16A-16D, the ranges over which the grasper assembly802 is in the open position, closed position, and transitioning betweenthe open and closed positions are illustrated. FIG. 16A, whichcorresponds to FIGS. 15A1 and 15A2, illustrates the spherical surface942 engaging the horizontal surface 860 of the grasper cam follower 830at a point immediately adjacent to the transitional surface 862 of thegrasper cam follower. Consequently, FIG. 16A illustrates an approximatefirst end point 990 of the first range of rotation of the crank 912during which the grasper assembly 802 is in the open position. FIG. 16B,which corresponds to FIGS. 15B1 and 15B2, shows the spherical surface942 engaging the horizontal surface 860 of the grasper cam follower 830at point immediately adjacent to the transitional surface 862 after thecrank 912 has rotated the camming structure 914 through approximately180 degrees relative to the position of the camming structure 914 shownin FIG. 16A. At this point, the grasper assembly 802 is still in theopen position. Consequently, FIG. 16B illustrates an approximate secondend point 992 of the first range. As illustrated, the range between thefirst and second end points 990, 992, relative to a center line 994, issomewhat less than 180 degrees.

With reference to FIG. 16C, which corresponds to FIGS. 15C1 and 15C2,the spherical surface 942 is not engaging the grasper cam follower 830and is positioned at a point immediately adjacent to the transitionalsurface 862. At this point, the grasper assembly 802 is in the closedposition. Consequently, FIG. 16C illustrates an approximate first endpoint 996 of the second range of rotation of the crank 912 during whichthe grasper assembly 802 is in the closed position. FIG. 16D, whichcorresponds to FIGS. 15D1 and 15D2, shows the spherical surface 942immediately adjacent to the transitional surface 862 of the grasper camfollower 830 after the crank 912 has rotated the camming structure 914through approximately 180 degrees relative to the position of thecamming structure 914 shown in FIG. 16C. Consequently, FIG. 16Dillustrates an approximate second end point 998 of the second range. Asillustrated, the range between the first and second end points 996, 998,relative to a center line 994, is somewhat less than 180 degrees.

Between the second end point 992 of the first range and the first endpoint 996 of the second range, the spherical surface 942 is engaging thetransitional surface 862 of the grasper cam follower 830 and the grasperassembly 802 is between the open and closed positions. Similarly,between the second end point 998 of the second range and the first endpoint 990 of the first range, the spherical surface 942 is engaging thetransitional surface 862 of the grasper cam follower 830 and the grasperassembly 802 is between the open and closed positions. When the grasperassembly 802 is between the open and closed positions, the ability ofthe grasper assembly 802 to grasp a cartridge is ambiguous.Consequently, the end points of the first and second ranges may lie inthe ranges associated with the transition of the grasper assembly 802between the open and closed positions. As such the first and secondranges may lie closer to 180 degrees or may exceed 180 degrees. In anyevent, the ranges are each approximately 180 degrees and do notsubstantially overlap.

It should be appreciated that picker can be designed such the grasper isin an open position for a first range of rotation of a crank and in aclosed position for a second range of rotation of the crank that doesnot substantially overlap with the first range of rotation where theranges are different than those illustrated in FIGS. 16A-16D.

With reference to FIGS. 12B, 13A and 13B, the library 100 furthercomprises a removable robotics module 740 that allows a user to readilyremove substantially all of the electrical and mechanical components ofthe transport system 112 that could break or malfunction from thelibrary 100 and replace all of those components by inserting anothermodule into the library 100. As a consequence, any downtime for thelibrary 100 that is associated with a broken or malfunctioning componentof the transport system 112 can be reduced.

The removable robotic module 740 comprises the robotic module tray 670and, attached to the tray 670, the picker 580, most of the elevator 582,and a controller board 742 that provides control logic for the picker580 and the elevator 582. The module 740 does not include the pulley692, the bracket 694, the second shaft pulley 696, the bracket 698, thethird timing belt 700, the portion of the connecting bracket 690 thatremains connected to the timing belt 700 after the quick release deviceis actuated, the second shaft piece 704, or the spline sleeve 708.

The tray 670 of the module 740 is fixed in place in the library 100 bybrackets 744A-744B that are attached to the side portion 184A of thebottom tray 186, brackets 746A-746B that are attached to the sideportion 184B of the bottom tray 186, a bracket 748 that is attached tothe mid-portion 190 of the bottom tray 186, and a threaded hole 750 thatreceives a captured screw 752 associated with the tray 670. The brackets744A, 744B, 746A and 746B operate to engage the edge of the tray 670 andthereby vertically constrain the tray 670. The bracket 748 engages theedge of the tray 670 to both vertically and horizontally constrain thetray 670. The threaded hole 750, when engaged by the screw 752, alsoserves to vertically and horizontally constrain the tray 670.

Assuming the removable robotic module 740 is fixed in place within thelibrary 100, removal of the module 740 involves: removing the frontpanel 176 to expose the module 740, unscrewing the screw 752 from thethreaded hole 750, manipulating the spline sleeve 708 to disconnect thefirst shaft piece 702 and the second shaft piece 704, and manipulatingthe connecting bracket 701 to disconnect the top plate 622 from thethird timing belt 700. In addition, an electrical connector thatconnects the controller board 742 and the control module 536 isdisconnected. After these operations are completed, the module 740 canbe slid out of the library 100 and, if desired, a replacement moduleinserted and connected to the library. After any replacement module hasbeen connected to the library 100, the front panel 176 is replaced.

The foregoing is intended to describe the best mode known of practicingeach of the inventions and to enable others skilled in the art topractice the inventions.

1. A data cartridge library comprising: a frame that defines an interiorspace; a data cartridge magazine, operatively attached to said frame andlocated within said interior space, for providing a plurality of datacartridge storage spaces; a drive, operatively attached to said frameand located within said interior space, for writing data onto arecording medium located within a data cartridge and/or reading datafrom a recording medium located within a data cartridge; a transportassembly, operatively attached to said frame and located within saidinterior space, for moving a data cartridge between said data cartridgemagazine and a drive that might be located in said drive bay, whereinsaid transport assembly comprises a picker that is capable of grasping adata cartridge and an elevator for moving said picker; an entry/exitport that allows an entry/exit port magazine to be moved between anexterior space that is outside of said frame and said interior space;wherein said entry/exit port comprises a mount to which an entry/exitport magazine can be attached and from which an entry/exit port magazinecan be detached, a guide for constraining said mount to move between afirst position at which a user can attach/detach an entry/exit portmagazine to/from said mount and a second position at which saidtransport assembly is capable of inserting/removing a data cartridgeinto/from an entry/exit port magazine attached to said mount, a motivedevice for providing a motive force for moving said mount between saidfirst and second positions, and a first stop structure that is attachedto said mount and engages a second stop structure to prevent said motivedevice from moving said mount beyond said first position; and a quickrelease that allows said first stop structure to be readily detachedfrom said mount so that said mount can be removed from the library.
 2. Adata cartridge library, as claimed in claim 1, wherein: said quickrelease structure comprises a screw.
 3. A data cartridge librarycomprising: a frame that defines a top surface, a bottom surface that isspaced from said top surface, and a side surface that extends betweensaid top and bottom surfaces; wherein said top, bottom and side surfacesdefine an interior space; a data cartridge magazine, located within saidinterior space, that is capable of holding a plurality of datacartridges; a drive, located within said interior space, for writingdata onto a recording medium located within a data cartridge and/orreading data from a recording medium located within a data cartridge; atransport assembly, located within said interior space, for moving adata cartridge between said data cartridge magazine and said drive,wherein said transport assembly comprises a picker that is capable ofgrasping a data cartridge and an elevator for moving said picker withina portion of said interior space; and a user interface that isassociated with said side surface and exposed to an exteriorenvironment; wherein said side surface comprises a displaceable portionthat is capable of being placed in: (a) an “open” state that allows auser to access said data cartridge magazine and said drive through saidinterior space, and (b) a “closed” state that prevents a user fromaccessing said data cartridge magazine and said drive through saidinterior space; wherein said displaceable portion defines an opening fora user interface; a user-actuatable connector that allows a user to: (a)place said displaceable portion in said “closed” state, and (b) placesaid displaceable portion in said “open” state; wherein saiduser-actuatable connector does not constrain said displaceable portionto rotate about an axis when moving between said “closed” and “open”states.
 4. A data cartridge library, as claimed in claim 3, wherein:said user-actuatable connector comprises a screw.
 5. A data cartridgelibrary, as claimed in claim 3, wherein: said user-actuatable connectorcomprises a captured screw.
 6. A data cartridge library, as claimed inclaim 3, wherein: said user-actuatable connector comprises a group ofscrews.
 7. A data cartridge library, as claimed in claim 3, wherein:said user-actuatable connector comprises a group of captured screws. 8.A data cartridge library, as claimed in claim 3, wherein: said connectorcomprises a buckle.
 9. A data cartridge library, as claimed in claim 3,wherein: said connector comprises a clasp.
 10. A data cartridge library,as claimed in claim 3, wherein: said user interface comprises anentry/exit port that allows a user to insert/remove a data cartridgeinto/from the interior space.
 11. A data cartridge library, as claimedin claim 3, wherein: said user interface comprises a electronic displaythat allows a user to obtain information about the library.
 12. A datacartridge library, as claimed in claim 3, wherein: said user interfacecomprises an input device that allows a user to direct an operation ofthe library.
 13. A data cartridge library, as claimed in claim 3,wherein: said user interface comprises: a entry/exit port that allows auser to insert/remove a data cartridge into/from the interior space; anelectronic display for providing a user with information; an inputdevice that allows a user to direct an operation of the library.
 14. Adata cartridge library, as claimed in claim 3, wherein: saiddisplaceable portion comprises a screen.
 15. A data cartridge library,as claimed in claim 3, wherein: said displaceable portion comprises awindow.
 16. A data cartridge library, as claimed in claim 3, wherein:said displaceable portion comprises a metal portion and a plasticportion.
 17. A data cartridge library, as claimed in claim 3, furthercomprising: a rail mount for mounting a rail that facilitates theassociation of the library with a rack.
 18. A multi-piece data cartridgemagazine that is suitable for use with a data cartridge librarycomprising: a channel structure that defines an interior space that iscapable of accommodating a plurality of data cartridges; wherein saidchannel structure comprises a first side with a first side interiorsurface and a first side exterior surface; wherein said channelstructure comprises a second side with a second side interior surfaceand a second side exterior surface; wherein said second side isseparated from said first side; wherein said channel structure comprisesa back side with a back side interior surface and a back side exteriorsurface; wherein said back side extends between said first and secondsides; wherein said first side interior surface, said second sideinterior surface, and said back side interior surface define saidinterior space; wherein said first and second sides define at least aportion of an opening for the insertion/extraction of data cartridgeinto/from said interior space; said channel structure comprising: afirst channel structure that forms at least a portion of said back side;a second channel structure that forms at least a first portion of saidfirst side and at least a second portion of said second side; and acoupler for connecting said first and second channel structures.
 19. Amulti-piece data cartridge magazine, as claimed in claim 18, wherein:said second channel structure comprises an end portion that connectssaid first and second portions.
 20. A multi-piece data cartridgemagazine, as claimed in claim 188 wherein: said end portion does notform a substantial portion of said back side.
 21. A multi-piece datacartridge magazine, as claimed in claim 18, wherein: said second channelstructure comprises: a first end portion that connects said first andsecond portions; and a second end portion that is separated from saidfirst end portion and connects said first and second portions.
 22. Amulti-piece data cartridge magazine, as claimed in claim 21, wherein:said first and second end portions each do not form a substantialportion of said back side.
 23. A multi-piece data cartridge magazine, asclaimed in claim 18, wherein: said first channel structure comprises: afirst channel structure first surface that forms a substantial portionof said first side of said channel structure; and a first channelstructure second surface that forms a portion of said back side of saidchannel structure.
 24. A multi-piece data cartridge magazine, as claimedin claim 23, wherein: said coupler comprises: a first coupler elementthat is associated with said first channel structure first surface; anda second coupler element that is associated with said first portion ofsaid first side formed by said second channel structure.
 25. Amulti-piece data cartridge magazine, as claimed in claim 24, wherein:said first coupler element comprises a recess/hole.
 26. A multi-piecedata cartridge magazine, as claimed in claim 24, wherein: said firstcoupler element comprises a flange.
 27. A multi-piece data cartridgemagazine, as claimed in claim 18, wherein: said first channel structurecomprises: a first channel structure first surface that forms a portionof said first side of said channel; a first channel structure secondsurface that forms a portion of said second side of said channel; and afirst channel structure back surface that forms a substantial portion ofsaid back side of said channel.
 28. A multi-piece data cartridgemagazine, as claimed in claim 27, wherein: said coupler comprises: afirst coupler element that is associated with said first channelstructure first surface; a second coupler element that is associatedwith said first channel structure second surface; a third couplerelement that is associated with said first portion of said first sideformed by said second channel structure; and a fourth coupler elementthat is associated with said second portion of said second side formedby said second channel structure.
 29. A multi-piece data cartridgemagazine, as claimed in claim 18, wherein: said portion of said backside comprises a stand-off structure for a data cartridge so that when adata cartridge that is properly positioned within said channelstructure, a first surface of the data cartridge contacts said stand-offstructure and a second surface of the data cartridge that is oppositefrom said first surface is at a predetermined distance from said backside.
 30. A multi-piece data cartridge magazine, as claimed in claim 18,wherein: said first channel structure is made of metal.
 31. Amulti-piece data cartridge magazine, as claimed in claim 18, wherein:said second channel structure comprises a retainer for engaging asurface associated with a data cartridge so as to hold the datacartridge within said channel structure.
 32. A multi-piece datacartridge magazine, as claimed in claim 18, wherein: said second channelstructure is made of plastic.
 33. A multi-piece data cartridge magazine,as claimed in claim 18, wherein: said second channel structure comprisesa plurality of separation structures that each comprise an end portionthat connects said first and second portions and does not form asubstantial portion of said back side.
 34. A multi-piece data cartridgemagazine, as claimed in claim 18, wherein: said coupler comprises: afirst coupler element associated with said first channel structure; anda second coupler element associated with said second channel structureand capable of engaging said first coupler element.
 35. A multi-piecedata cartridge magazine, as claimed in claim 34, wherein: one of saidfirst and second coupler elements comprises a spring element.
 36. Amulti-piece data cartridge magazine, as claimed in claim 18, wherein:said first channel structure comprises a surface that forms asubstantial portion of said back side of said channel structure; andsaid coupler comprises a recess/hole that is defined by said surface.37. A multi-piece data cartridge magazine, as claimed in claim 18,wherein: said first channel structure comprises a surface that forms asubstantial portion of said back side of said channel structure; andsaid coupler comprises a pair of recesses/holes that are each defined bysaid surface.
 38. A multi-piece data cartridge magazine, as claimed inclaim 18, wherein: said first channel structure comprises a surface thatforms a substantial portion of said back side of said channel structure;and said coupler comprises a coupler element that extends away from saidsurface.
 39. A multi-piece data cartridge magazine, as claimed in claim18, wherein: said first channel structure comprises a surface that formsa substantial portion of said back side of said channel structure; andsaid coupler comprises a pair of coupler elements that each extend awayfrom said surface.
 40. A multi-piece data cartridge magazine that issuitable for use with a data cartridge library comprising: a channelstructure that defines an interior space that is capable ofaccommodating a plurality of data cartridges; wherein said channelstructure comprises a first side with a first side interior surface anda first side exterior surface; wherein said channel structure comprisesa second side with a second side interior surface and a second sideexterior surface; wherein said second side is separated from said firstside; wherein said channel structure comprises a back side with a backside interior surface and a back side exterior surface; wherein saidfirst side interior surface, said second side interior surface, and saidback side interior surface define said interior space; wherein saidfirst and second sides define at least a portion of an opening for theinsertion/extraction of data cartridge into/from said interior space;said channel structure comprising: a first channel structure thatcomprises a first channel structure first surface that forms a portionof said first side of said channel, a first channel structure secondsurface that forms a portion of said second side of said channel, and afirst channel structure back surface that forms a substantial portion ofsaid back side of said channel; a second channel structure thatcomprises a second channel structure first surface that forms a portionof said first side of said channel and a second channel structure secondsurface that forms a portion of said second side of said channel; and acoupler for connecting said first and second channel structures.
 41. Amulti-piece magazine, as claimed in claim 40, wherein: said secondchannel structure comprises a second channel structure third surfacethat connects said second channel structure first and second surfaces.42. A multi-piece magazine, as claimed in claim 40, wherein: said secondchannel structure comprises: a second channel structure third surfacethat connects said second channel structure first and second surfaces;and a second channel structure fourth surface that is separated fromsaid second channel structure third surface and connects said secondchannel structure first and second surfaces.
 43. A multi-piece magazine,as claimed in claim 40, wherein: said first channel structure is made ofmetal; and said second channel structure is made of plastic.
 44. A datacartridge library comprising: a frame that defines a top surface, abottom surface that is spaced from said top surface, and a side surfacethat extends between said top and bottom surfaces; a data cartridgemagazine; a drive, operatively attached to said frame, for writing dataonto a recording medium located within a data cartridge and/or readingdata from a recording medium located within a data cartridge; atransport assembly, operatively attached to said frame, for moving adata cartridge between said data cartridge magazine and said drive,wherein said transport assembly comprises a picker that is capable ofgrasping a data cartridge and an elevator that is capable of moving saidpicker; wherein said data cartridge magazine comprises: a first side, asecond side that is separated from said first side, and back side thatextends between said first and second sides; wherein said first, secondand back sides define a channel with an interior space that is capableof accommodating a plurality of data cartridges; a first channelstructure that forms at least a portion of said back side; a secondchannel structure that forms at least a portion of at least one of saidfirst and second sides; and a coupler for connecting said first andsecond channel structures; wherein said frame comprises at least aportion of said first channel structure.
 45. A data cartridge library,as claimed in claim 44, wherein: a portion of said frame defines saidside surface; and at least a portion of said first channel structuredefines at least a portion of said side surface.
 46. A data cartridgelibrary, as claimed in claim 44, wherein: said first channel structureis made of metal.
 47. A data cartridge library, as claimed in claim 44,wherein: said second channel structure is made of the same class ofmaterials as is used to make a housing of a data cartridge.
 48. A datacartridge library, as claimed in claim 44, wherein: said second channelstructure is made of plastic.
 49. A data cartridge library, as claimedin claim 44, wherein: said second channel structure comprises a retainerwith a surface for engaging a data cartridge and spring element forurging said surface into engagement with a data cartridge.
 50. A datacartridge library comprising: a frame that defines an interior space; adata cartridge magazine, located within said interior space, that iscapable of holding a plurality of data cartridges; a drive bay, locatedwithin said interior space, for accommodating at least one full heightdrive; a transport assembly, located within said interior space, formoving a data cartridge between said data cartridge magazine and a drivethat might be located in said drive bay, wherein said transport assemblycomprises a picker that is capable of grasping a data cartridge and anelevator for moving said picker; wherein said drive bay defines a firstopening, a second opening, and a drive space that extends between saidfirst and second openings; wherein said first opening allows saidtransport assembly to insert/retract a data cartridge into/from anydrive that is located in said drive space; wherein said second openingallows a user to install/remove a drive into/from said drive bay;wherein said drive bay comprises a partition mount for supporting apartition that divides said drive space such that a full-height drivespace that is located within said drive space and capable ofaccommodating a full-height drive provides first and second half-heightdrive spaces that are each capable of accommodating a half-height drive.51. A data cartridge library, as claimed in claim 50, furthercomprising: a partition for engaging said partition mount in said drivebay.
 52. A data cartridge library, as claimed in claim 50, wherein: saidfull height drive space is capable of accommodating: (a) a full-heightdrive that is located within a full-height drive sled or (b) when apartition is engaged to said partition mount within said drive bay, afirst half-height drive that is located within a first half-height drivesled that is located with said first half-height drive space, and asecond half-height drive that is located within a second half-heightdrive sled that is located within said second half-height drive space.53. A data cartridge library, as claimed in claim 50, wherein: saiddrive bay comprises: a first drive bay electrical connector thatinterfaces to said first half-height drive space; and a second drive bayelectrical connector that interfaces to said second half-height drivespace.
 54. A data cartridge library, as claimed in claim 53, wherein:said first and second drive bay electrical connectors each face towardssaid second opening.
 55. A data cartridge library comprising: a framethat defines an interior space; a data cartridge magazine, locatedwithin said interior space, that is capable of holding a plurality ofdata cartridges; a drive bay, located within said interior space, foraccommodating a plurality of full height drives; a transport assembly,located within said interior space, for moving a data cartridge betweensaid data cartridge magazine and a drive that might be located in saiddrive bay, wherein said transport assembly comprises a picker that iscapable of grasping a data cartridge and an elevator for moving saidpicker; wherein said drive bay defines a first drive space that extendsbetween first drive space first and second openings and is capable ofaccommodating a first full-height drive; wherein said drive bay definesa second drive space that extends between second drive space first andsecond openings and is capable of accommodating a second full-heightdrive; wherein said first drive space first opening allows saidtransport assembly to insert/retract a data cartridge into/from a drivethat is located in said first drive space; wherein said first drivespace second opening allows a user to install/remove a drive into/fromsaid first drive space; wherein said second drive space first openingallows said transport assembly to insert/retract a data cartridgeinto/from a drive that is located in said second drive space; whereinsaid second drive space second opening allows a user to install/remove adrive into/from said second drive space; wherein said drive baycomprises a partition mount for supporting a partition that divides saidfirst drive space into first and second half-height drive spaces thatare each capable of accommodating a half-height drive.
 56. A datacartridge library, as claimed in claim 55, further comprising: apartition engaging said partition mount.
 57. A data cartridge library,as claimed in claim 56, further comprising: a half-height drive locatedin one of said first and second half-height drive spaces.
 58. A datacartridge library, as claimed in claim 56, further comprising: a firsthalf-height drive located in said first half-height drive space; and asecond half-height drive located in said second half height drive space.59. A data cartridge library, as claimed in claims 57 or 58, furthercomprising: a full-height drive located in said second drive space. 60.A data cartridge library, as claimed in claim 55, further comprising: afirst full height drive located in said first drive space; and a secondfull height drive located in said second drive space.
 61. A datacartridge library comprising: a frame that defines an interior space;data cartridge space, located within said interior space, for providingdata cartridge storage locations for all of the data cartridges that thelibrary is capable of storing; drive space, located within said interiorspace, for providing drive locations for all of the drives that thelibrary is capable of accommodating; transport assembly space, locatedwithin said interior space, for accommodating the operation of a pickerand an elevator in moving a data cartridge between any of said datacartridge storage locations in said data cartridge space and any drivelocations in said drive space; power supply space, located within saidinterior space, for accommodating all of the power supplies that thelibrary is capable of accommodating; circuitry space, located withinsaid interior space, for accommodating circuitry for distributing powerand controlling said transport assembly; and a universal bay, locatedwithin said interior space, that defines a universal space that iscapable of accommodating electronic circuitry other than electroniccircuitry that is located in said circuitry space and that does notcomprise said frame, said data cartridge space, said drive space, saidtransport assembly space, said power supply space or said circuitryspace.
 62. A data cartridge library, as claimed in claim 61, wherein:said universal bay comprises a connector board with one or more firstelectrical connectors for establishing electrical connections withelectronic circuitry that may be located in said universal space.
 63. Adata cartridge library, as claimed in claim 62, further comprising: acard cage, located in said universal space, with one of more secondelectrical connectors that are each capable of establishing anelectrical connection with a corresponding one of said one or more firstelectrical connectors associated with said connector board.
 64. A datacartridge library, as claimed in claim 63, wherein: said card cagecomprises a compact peripheral component interconnect.
 65. A datacartridge library, as claimed in claim 63, wherein: said card cagecomprises one of the following: a 3 U high card cage and a 6 U high cardcage.
 66. A data cartridge library, as claimed in claim 62, furthercomprising: a quad interface processor located in said universal space,with one of more second electrical connectors that are each capable ofestablishing an electrical connection with a corresponding one of saidone or more first electrical connectors associated with said connectorboard.
 67. A data cartridge library, as claimed in claim 61, wherein:said universal bay comprises: a first connector board with one or morefirst electrical connectors for establishing electrical connections withfirst electronic circuitry that may be located in a first universalspace within said universal space; and a second connector board with oneor more first electrical connectors for establishing electricalconnections with second electronic circuitry that may be located in asecond universal space within said universal space that does not includesaid first universal space.
 68. A data cartridge library, as claimed inclaim 67, wherein: said universal bay comprises a partition mount forsupporting a partition that divides said universal space into said firstand second universal spaces.
 69. A data cartridge library, as claimed inclaim 68, wherein: said universal bay comprises a partition for engagingsaid partition mount to divide said universal space into said first andsecond universal spaces.
 70. A data cartridge library, as claimed inclaim 67, further comprising: a first card cage, located in said firstuniversal space, with one of more second electrical connectors that areeach capable of establishing an electrical connection with acorresponding one of said one or more first electrical connectorsassociated with said first connector board; and a second card cage,located in said second universal space, with one of more secondelectrical connectors that are each capable of establishing anelectrical connection with a corresponding one of said one or more firstelectrical connectors associated with said second connector board.
 71. Adata cartridge library, as claimed in claim 67, further comprising: afirst quad interface processor, located in said first universal space,with one of more second electrical connectors that are each capable ofestablishing an electrical connection with a corresponding one of saidone or more first electrical connectors associated with said firstconnector board; and a second quad interface processor, located in saidsecond universal space, with one of more second electrical connectorsthat are each capable of establishing an electrical connection with acorresponding one of said one or more first electrical connectorsassociated with said second connector board.
 72. A data cartridgelibrary, as claimed in claim 67, further comprising: a card cage,located in said first universal space, with one of more secondelectrical connectors that are each capable of establishing anelectrical connection with a corresponding one of said one or more firstelectrical connectors associated with said first connector board; and aquad interface processor, located in said second universal space, withone of more second electrical connectors that are each capable ofestablishing an electrical connection with a corresponding one of saidone or more first electrical connectors associated with said secondconnector board.
 73. A data cartridge library comprising: a frame thatdefines an interior space; data cartridge space, located within saidinterior space, that contains a magazine structure for holding datacartridges and that provides data cartridge storage locations for all ofthe data cartridges that the library is capable of storing; drive space,located within said interior space, that contains at least one drive andprovides drive locations for all of the drives that the library iscapable of accommodating; transport assembly space, located within saidinterior space, that contains a picker that is capable of grasping adata cartridge and an elevator for moving said picker, and that providesspace for accommodating the operation of said picker and said elevatorin moving a data cartridge between any one of said data cartridgestorage locations in said data cartridge space and any drive location insaid drive space; power supply space, located within said interiorspace, that contains at least one power supply and provides space foraccommodating all of the power supplies that the library is capable ofaccommodating; circuitry space, located within said interior space, thatcontains circuitry for distributing power and for controlling saidpicker and said elevator; and a universal bay, located within saidinterior space, that defines a universal space which is capable ofaccommodating electronic circuitry other than electronic circuitry thatis located in said circuitry space and which is not within saidtransport assembly space.
 74. A data cartridge library, as claimed inclaim 73, wherein: said universal space adjoins said data cartridgespace.
 75. A data cartridge library, as claimed in claim 73, wherein:said universal space adjoins said drive space.
 76. A data cartridgelibrary, as claimed in claim 73, wherein: said universal space adjoinssaid data cartridge space and said drive space.
 77. A data cartridgelibrary, as claimed in claim 73, wherein: said universal space adjoinssaid transport assembly space.
 78. A data cartridge library, as claimedin claim 73, wherein: the location of at least one of said datacartridge space and said drive space prevent said picker from accessingsaid universal space.
 79. A data cartridge library, as claimed in claim73, wherein: the locations of said data cartridge space and said drivespace prevent said picker from accessing said universal space.
 80. Adata cartridge library comprising: a frame that defines an interiorspace; a data cartridge magazine, operatively attached to said frame andlocated within said interior space, for providing a plurality of datacartridge storage spaces; a drive, operatively attached to said frameand located within said interior space, for writing data onto arecording medium located within a data cartridge and/or reading datafrom a recording medium located within a data cartridge; a picker thatis capable of grasping a data cartridge, releasing a grasped datacartridge, inserting a grasped data cartridge into a data cartridgestorage space in said data cartridge magazine, inserting a grasped datacartridge into said drive, retracting a grasped data cartridge from adata cartridge storage space in said data cartridge magazine, andretracting a grasped data cartridge from said drive; and an elevator formoving said picker such that said picker can perform grasping,retracting and inserting operations in the moving of a data cartridgebetween any one of said data cartridge storage spaces and said drive;and wherein said elevator comprises: an electric motor; an elevatorcarriage have a first end and a second end that is separated from saidfirst end; a first drive system for applying a force to said first endof said elevator carriage; a second drive system for applying a force tosaid second end of said elevator carriage; and a shaft for transferringa force from said first drive system to said second drive system.
 81. Adata cartridge library, as claimed in claim 80, wherein: said shaftcomprises: a first shaft portion that is operatively connected to saidfirst drive system; a second shaft portion that is operatively connectedto said second drive system; and a user-actuatable connector forconnecting said first shaft portion and said second shaft portion.
 82. Adata cartridge library, as claimed in claim 81, wherein: a slidablespline sleeve associated with the other of said first and second shaftportions.